A moist muffin filled with juicy blueberries and topped with a buttery crumble.
Preheat oven to 375. Combine blueberries and 1 Tbls flour in a small bowl. Mix until blueberries are coated well. Set aside. Whisk together egg, oil, sour cream, and milk in a large mixing bowl. Combine flour, baking soda, baking powder, salt, and nutmeg in a medium mixing bowl. Slowly add dry ingredient mixture to wet. Stir until combined. Fold in blueberries. Fill paper-lined muffin tins 3/4 full. Meanwhile, combine streusel ingredients with a pastry cutter. Sprinkle streusel on top of each muffin. Bake for 20-25 minutes. Allow cooling before removing from muffin tins.