1. Preheat oven to 400 and spray muffin tins with cooking spray.
2. Combine dry ingredients and make a well in the center.
3. Add wet ingredients and stir to combine. You want to just combine, not stir until very smooth.
4. If you are using frozen berries, thaw and then dust lightly with flour to keep berries from sinking to the bottom. Gently stir in blueberries.