by Olena

Blueberry Crumble Bars

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Olena Osipov
5 from 4 votes

These Healthy Blueberry Crumble Bars are wholesome, decadent, and packed with juicy blueberries for a fresh and fruity treat any time of the day (or year!). Even better, these healthy blueberry oatmeal bars swap out regular white flour, sugar, and butter for healthier substitutes you can feel less guilty about indulging in (and they still taste indulgent)!

Love grab n’ go oatmeal treats? You’ll also love these apple oatmeal bars, baked oatmeal breakfast bars, or even oatmeal cookies!

blueberry crumb bars cut into squares

Fresh and Fruity Healthy Blueberry Crumble Bars

I’ll be honest, my mom was never much of a baker (though she taught me lots of my favorite Ukrainian classics!), but she did enjoy making cobblers and crumb bars with lots of jam. These days I omit the sugary jam, filling my blueberry crumble bars with lots of fresh, bursting blueberries in every single bite (nothing messy, don’t panic!). 

Unlike traditional blueberry oatmeal crumble bars, I’ve made my version healthier using whole wheat flour, oats, applesauce, coconut oil, and unrefined sugars. However, even with the lack of butter and sugar, these blueberry bars are amazing; tender, chewy, crisp, and super fruity! Best of all, you can use fresh or frozen berries to enjoy this blueberry crumble recipe any time of the year (like these healthy lemon bars)! 

During summer, I love to buy my blueberries organic from farmers’ markets. I also definitely recommend visiting a pick-your-own farm, too, if you have one nearby. The kids will love it AND will sit eating fruit in the back of the car all the way home (now that’s an easy way to get them to eat more fruit!). Any blueberries you have remaining when you finally get home are perfect for whipping up a batch of these blueberry crumble bars ( and healthy blueberry muffins, almond flour blueberry muffins or blueberry coffee cake). 

Plus, if you love blueberries as much as I do – then you’ll want them for every meal of the day; blueberry breakfast cake for breakfast, kale blueberry salad for lunch, blueberry quinoa dish for dinner – and of course, these blueberry crumb bars for when the sugar cravings hit!

These healthy blueberry oatmeal bars are also an excellent option to bring to picnics, potlucks, BBQs, and summer parties. I’ve never had any leftovers!

Why This Blueberry Crumble Recipe Works?

  • These blueberry crumble bars are very versatile – swap out the fruit based on what’s in season (or your freezer)! Use other berries, apples, peach, etc. 
  • They are also almost entirely made up of pantry basics!
  • These can be made with fresh or frozen fruit so you can enjoy healthy blueberry oatmeal bars no matter the time of year!
  • All you need is 12 ingredients and 15 minutes of prep for these blueberry oatmeal crumble bars!
  • Enjoy these as a healthy grab n’ go breakfast, mid-day snack, or even dessert!
  • These combine the soft fruity middle with a tender, chewy, crisp biscuity base and crumble topping – texture heaven!
blueberry crumble bars resting on cooling rack

Ingredients for Blueberry Oatmeal Crumble Bars

The Crust

  • Oats: quick or rolled oats will work. Use gluten-free certified oats if necessary. 
  • Flour: I recommend using whole wheat or spelt flour (which I use a lot for muffins and quick breads!), though white flour will also work. For gluten-free blueberry crumble bars, you may be able to use a general gluten-free all-purpose blend. I don’t recommend using almond flour or coconut flour, though, as their absorbency levels will impact the dough and would need additional tweaks. 
  • Sugar: I recommend using maple syrup, cane sugar, or coconut sugar. Read the recipe notes on how they impact the healthy blueberry oatmeal bars. 
  • Baking powder: Will leaven and help to provide a little lift and texture to the crust.
  • Cinnamon: Technically optional, but delicious. 
  • Salt: Just a little to enhance and add depth to the flavors.
  • Egg: Just one egg is needed as a binder. Check the FAQs for substitutes. 
  • Coconut oil: I used room temperature coconut oil (not melted) in place of butter in this blueberry oatmeal crumble bars recipe. You may also be able to use softened butter, but I haven’t tried. Don’t reduce the amount, or you can end up with a crumble that’s too dry and crumbly. 
  • Applesauce: sweetened or unsweetened applesauce will work for this recipe – but adjust the sugar accordingly. 
  • Cooking spray: Needed for the baking pan. 

The Blueberry Filling

  • Blueberries: You can use fresh or frozen (thawed in hot water). This recipe works the same with several berries; raspberries, blackberries, Saskatoon berries, etc. You could also use peaches or apples even. 
  • Sugar: Same as for the crust – use either granulated or maple. 
  • Citrus: You can use orange or lemon zest for an added layer of brightness and flavor to the blueberry crumble bars.
  • Vanilla: Just a little vanilla extract for tons of dessert-y flavor!
  • Cornstarch: Will help to thicken any bursting berries into a jam-like consistency.

Keep reading below for a section on optional add-ins!

blueberry crumble bars ingredients

How to Make Healthy Blueberry Oatmeal Bars

  • Prepare the pan: First, preheat the oven to 350F/176C, and line an 8×8-inch baking dish with parchment paper and cooking spray. 
  • Combine the crusts’ dry ingredients: In a large bowl, add the oats, flour, sugar (unless you’re using maple- then add that with the liquids), baking powder, cinnamon, and salt. Mix well. 
  • Add the wet ingredients: Add the egg, coconut oil, maple syrup (if using) and applesauce and mix with a spatula, changing to your hands towards the end until everything is incorporated. The dough should be moist and in one piece, not crumbly. 
  • Prepare the blueberry crumble filling: In a medium bowl, combine the blueberries, maple syrup (or sugar), orange zest, vanilla, cornstarch, and mix. 
  • Assemble the healthy blueberry oatmeal bars: Press ¾ of the crust dough into the prepared baking dish, flatting it with a spatula/your hands (press tightly to compact it into a nice ‘cookie’-like layer). Then, spread the blueberry filling over the top before crumbling the remaining crust dough over the top in small crumbs (which make the pieces easier to slice after baking). 

The sugar you use will impact the crumb size. Granulated sugar helps to make smaller crumbs, but maple syrup will be slightly larger. Also, don’t worry if the blueberry filling has some liquid in it; it will thicken up as it bakes. 

  • Bake the blueberry crumble bars: Bake for 45 minutes, then remove from the oven and cool completely before slicing into 16 squares.

Make sure to allow the blueberry oatmeal crumble bars to cool before slicing the squares, as it helps the filling to thicken up further. Otherwise, you’ll end up with filling oozing all over the place.

My boys loved these except my little one. Oh well, he gets clean eating banana muffins from the freezer then!

Tips

  • Your choice of sugar: I’ve included granulated, and liquid options as the ‘sugar’ in this healthy blueberry crumble recipe. I’ve tried both and prefer granulated as it’s closer to the taste and texture of regular crumb bars. Maple syrup yields a fluffier for ‘cakey’ crust. 
  • Experiment with fruit: Based on what’s in season, in your fridge or freezer – there are several types of fruit you can use to create delicious, fruity healthy crumble bars. Just make sure to use the same amount, and you’re set!
  • To quickly soften coconut oil: Depending on the weather, your coconut oil might be in its solid-state. To quickly soften it, transfer the amount you need to a small bowl or jar and place that over (or in, if using a jar) a dish of hot water for a few minutes. Soon the coconut oil will be soft like butter (without having completely melted!). 
  • The ratio of topping: Lots of recipes call for half of the crust to be used as the topping. However, that will completely cover your berries. I prefer to use ⅓ for a thicker biscuity base and a light coating on top with berried peeking through. 
  • Be careful not to overbake: Or else the blueberry crumble bars can become very difficult to slice!

Add-ins and Variations

  • Chia seeds: Adding some chia seeds to the blueberry oatmeal crumble bars will further help to turn the filling into a jammy consistency. It will also add extra protein to the recipe. 
  • Nuts: You could add some crushed nuts to the top crumble for extra protein and heart-healthy fats. I recommend walnuts!
  • Chocolate: For a little more of a decadent result, you can sprinkle over a few chocolate chips (sugar-free if preferred). 
  • Glaze: You could also make a quick sweet glaze. Keep the sugar content low by using a combination of powdered erythritol with a bit of vanilla extract and milk or water.  Alternatively, combine the cream from a can of coconut milk with a little maple syrup and drizzle over the top.

FAQs

Can I make this blueberry crumble recipe egg-free?

As only one egg is required, it may be possible to substitute it with an egg replacement like a chia/flax egg or adding an extra ¼ cup applesauce (or banana) to the recipe. However, the fruit purees will yield a denser result.

Can I use frozen berries for blueberry crumble bars?

You sure can – in fact, I prefer using frozen blueberries for this blueberry crumble recipe. That way, you can make them year-round and even save money; best of all, though, I’ve found that frozen blueberries ‘pop’ more while baking for more of a jam-like filling – it’s delicious!

Just make sure to thaw and drain the blueberries first, so the bars don’t become soggy while baking.  Oh, and if you like baking with fresh or frozen berries, check out my whole wheat coffee cake and almond muffins.

Serving Recommendations

There are several ways to enjoy this blueberry crumble recipe, whether it’s as a quick breakfast, snack, or dessert. You can also enjoy these bars warm or chilled. 

  • Eat the healthy blueberry oatmeal bars alone as a breakfast or quick snack.
  • Serve up with yogurt for breakfast.
  • Eat a blueberry crumble bar with a scoop of ice cream or frozen yogurt for a hearty, wholesome dessert.
  • Pour over a little custard for a delicious dessert – I recommend warming it up for this version.

Making Blueberry Crumble Recipe in Advance

Make-Ahead: You can prepare the assembled unbaked blueberry crumble bars and store them, covered, in the refrigerator for up to a day before baking. Alternatively, freeze for between 2-3 months. You can then either thaw the unbaked bars before baking or bake from frozen, adding extra time until the topping is golden and the blueberry filling begins to bubble. 

Store: Store the blueberry crumble bars in a cool, dry place at room temperature for 3 days or refrigerate in an airtight container for up to 5 days. 

Freeze: Allow the blueberry crumb bars to cool entirely before transferring to an airtight container (leaving spaces in-between and with layers of parchment between layers) and freeze for up to three months. Note that the crisp texture of the crumble topping will soften upon thawing – but they’ll taste delish!

Reheat: You can reheat the blueberry oatmeal crumble bars in the microwave (individually) for around 30 seconds or until warm.

More Healthy Sweet Treats to Try

Or you can look through my entire list of healthy desserts, for more inspiration!

blueberry crumb bars
Blueberry Crumble Bars

Blueberry Crumble Bars {Healthy}

These healthy Blueberry Crumble Bars are wholesome, decadent, and packed with juicy blueberries for a fresh and fruity treat any time of the day (or year!). Even better, these healthy blueberry oatmeal bars swap out regular white flour, sugar, and butter for healthier substitutes you can feel less guilty about indulging in (and they still taste indulgent)!
5 from 4 votes
Print Save Rate
Course: Dessert
Cuisine: American
Prep Time: 15 minutes
Cook Time: 45 minutes
Chill Time: 1 hour
Total Time: 2 hours
Servings: 16 bars
Calories: 187kcal
Author: Olena Osipov

Ingredients

Crust:

  • 2 cups quick or rolled oats
  • 1 1/4 cups whole wheat or spelt flour
  • 1/2 cup maple syrup, cane sugar or coconut palm sugar
  • 1/2 tsp baking powder aluminum free
  • 1/2 tsp cinnamon
  • 1/4 tsp salt
  • 1 egg large
  • 1/2 cup coconut oil room temperature (not melted)
  • 1/4 cup applesauce sweetened or unsweetened (1/2 cup if using sugar)
  • Cooking spray I use Misto

Blueberry Filling:

  • 3 cups blueberries fresh or frozen (if using frozen thaw in hot water & drain)
  • 2 tbsp maple syrup, cane or coconut palm sugar
  • 1 orange or lemon zest of
  • 1 tsp pure vanilla extract
  • 1 tbsp cornstarch

Instructions

  • Preheat oven to 350 degrees F, line square 8" x 8" baking dish with unbleached parchment paper and spray with cooking spray.
    Blueberry Crumble Bars
  • In a large mixing bowl, add oats, flour, cane or coconut palm sugar (if using maple syrup add it later with liquids), baking powder, cinnamon and salt; mix well with spatula.
    Blueberry Crumble Bars
  • Add maple syrup (only if not using sugar), egg (quickly whisked in a small bowl), coconut oil and applesauce. Mix with a spatula and with your hands more towards the end until well incorporated. Dough will be moist and should stick to one piece, not crumbly.
    Blueberry Crumble Bars
  • In a medium bowl, add blueberries, maple syrup (sugar), orange zest, vanilla, cornstarch and stir well.
    Blueberry Crumble Bars
  • Place 3/4 dough in prepared baking dish, flatten with spatula and press well with your hands.
    Blueberry Crumble Bars
  • Spread blueberry filling on top evenly and crumble remaining dough on top. Make sure crumbs are small – will be easier to achieve with sugar dough, and crumb will be bigger with maple syrup dough.
    Blueberry Crumble Bars
  • Bake for 45 minutes. Remove from the oven and let cool completely before slicing into 16 squares.
    Blueberry Crumble Bars

Make-Ahead: Prepare the assembled unbaked blueberry crumble bars and store them, covered, in the refrigerator for up to a day before baking. Alternatively, freeze for between 2-3 months. You can then either thaw the unbaked bars before baking or bake from frozen, adding extra time until the topping is golden and the blueberry filling begins to bubble. 

    Store: Store in a cool dry place for up to 3 days, refrigerate in an airtight container for up to 5 days.

      Freeze: Freeze in an airtight container for up to 3 months.

        Notes

        • Sweetener of choice: I have included 2 sweetener options: maple syrup or cane/coconut palm sugar. I tried both and I personally prefer the sugar version because bars and their crumb taste and look more like the original. With maple syrup, the bottom layer was a bit fluffier and cake-y but still delicious. So, up to you what you choose as I know some of you use sugar and some follow refined sugar free diet. You can also use regular white sugar. 🙂
        • Fresh or frozen blueberries? I also prefer to use frozen blueberries (make year round and save money, usually most recipes benefit from fresh berries). They pop during baking creating a nice singly thick layer of jam like filling. Fresh blueberries work as well but I found they don’t pop as much during baking and stick out. Which is fine as well.
        • Flour: You can use only whole wheat or spelt flour. Maybe gluten free flour blend or white flour will work. Almond flour or coconut flours will not work.
        • Butter: I have not tested but I think it will work. Just make sure it is very soft so you can crumble it.
        • Other berries: Raspberries, blackberries, Saskatoon berries will work.
        Significantly adapted from this recipe.:)

        Nutrition

        Serving: 1bar | Calories: 187kcal | Carbohydrates: 27g | Protein: 3g | Fat: 8g | Saturated Fat: 6g | Cholesterol: 10mg | Sodium: 58mg | Potassium: 126mg | Fiber: 3g | Sugar: 11g | Vitamin A: 33IU | Vitamin C: 4mg | Calcium: 35mg | Iron: 1mg
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        olena osipov in the studio

        Hello and welcome to iFOODreal.

        My name is Olena Osipov. I'm a mom to 2 boys, a wife to Alex and we reside on magical Vancouver Island in British Columbia, Canada. This is our healthy family recipes blog. Originally from Ukraine, I grew up on real food. As an adult, I struggled with diets for years because none worked long-term. Now for over 10 years, I cook easy healthy meals for my family. I can help you with “What’s for dinner?” too.

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