Preheat the oven to 375 degrees F. Lightly grease a 12-cup muffin tin with cooking spray. Set aside.
In a large bowl (or the bowl of an electric stand mixer), beat together the butter, yogurt and sugars until the mixture is light and fluffy. Add the eggs and beat well. In a blender or food processor, process the oats until they are finely ground. Add the wheat flour, baking soda and salt and pulse one or two times until the dry ingredients are lightly combined. Pour the dry mixture into the wet mixture and mix until just combined. Mix in the lightly mashed bananas. Stir in the milk and vanilla. Toss the blueberries with the 2 teaspoons flour and then gently fold them into the muffin batter. Divide the batter evenly among the 12 muffin cups. Bake for 20-22 minutes or until a toothpick inserted in the center comes out clean (watch the muffins carefully since each oven may vary slightly in temperature affecting exact baking time). Let the muffins rest in the pan for about 5 minutes and then turn out onto a wire rack to cool completely.