Warm up milk to 110 degrees F by placing in a microwave for 40 seconds or on the stove. It should be warm to the touch. Add melted butter and sugar, then whisk. Sprinkle yeast, gently stir and let stand until foamy, about 10 minutes.
Add eggs and whisk until mixed. Add 2 cups all-purpose flour and 1 cup whole wheat flour. Stir with wooden spoon, cover with linen towel and let stand in warm place for 1 hour or until doubled in size. This may take more or less time depending on the humidity and temperature in your home.
Preheat oven to 350 degrees F and butter large 9 x 13 baking dish, set aside. Sprinkle remaining 1/3 cup flour, baking powder and salt. Stir with spatula until can't stir any further, then knead on a floured surface for about 3-4 minutes.
Roll out dough into a 16 x 12 inch rectangle with shorter side closer to you. Spread softened butter over dough, leaving a 1/4 inch margin at the far 12 inch side of the dough.
In a small bowl, combine sugar and cinnamon, mix. Sprinkle all over buttered part. Starting at 12 inch side, roll the dough as tightly as possible, pinch the seam and place the seam side down.
Using a sharp knife or dental floss (my favorite), cut off 1/2 inch without the filling on each end. Then cut into even about 1 inch pieces and place into previously prepared dish.
Bake for 20-25 minutes or until just lightly golden brown. You do not want to bake cinnamon rolls longer so they stay soft. Remove from the oven and let cool a bit.
To make the frosting, in a medium bowl, add cream cheese, butter, powder sugar and vanilla. Beat with an electric hand mixer until smooth and fluffy. Spread over warm cinnamon rolls and enjoy!
Notes
Flours: You can use ALL white whole wheat flour. Substitute spelt flour with whole wheat flour. You can't use all whole wheat or spelt flour because all my tests didn't produce tasty results.
Healthier frosting:In a medium bowl, whisk 1 cup Greek yogurt, 1/4 cup maple syrup and 1/2 teaspoon vanilla. Add it not more than an hour before serving.