In a medium bowl, add milk and vinegar or lemon juice. Stir and let stand for 10 minutes. It should curdle somewhat and become "buttermilk" or also known as 'sour milk'.
In a large bowl, add "buttermilk", eggs, oil, maple syrup, baking soda, baking powder and salt. Whisk very well until combined. Add flour and mix gently with spatula until combined and no lumps.
Preheat ceramic non-stick griddle or large skillet on medium-high heat. Important for it to be hot, so oil sizzles when added. Swirl and spread a bit of oil to coat the surface. Using 1/3 cup measuring cup, spread batter in a circle shape and top with desired amount of blueberries. Cook for 3-4 minutes or until bubbles appear on top.
Flip, press on pancake gently with spatula and cook for another minute or so. You will have to reduce heat as skillet heats up during cooking. Watch carefully. Repeat until run out of batter.
Serve hot with butter, maple syrup, yogurt, sour cream etc.
Notes
Store: We never have pancakes past day 1 when we keep them in a dish covered with towel on a counter.
Freeze: Place in an airtight container for up to 3 months. Thaw on the counter overnight or pop in toaster from frozen.
Buttermilk: You can also use 1 3/4 cups regular buttermilk or leftover whey from Instant Pot yogurt production instead of milk. Skip vinegar then.
Other flour: You might be able to use equal amount of all-purpose flour.
Milk and vinegar: I have tried this recipe with dairy milk and almond milk, also with apple cider vinegar. All work.