Preheat oven to 400F.

Spray 16-18 cup muffin tin with baker's release spray, heavily grease, or use paper liners.

Mix dry ingredients in mixing bowl, then add blueberries and toss to coat with the flour.

Mix the other wet ingredients separately then stir them gently into the flour and blueberries to combine.

Divide batter among muffin cups.

Mix the oats and flour for a topping and sprinkle onto batter and tap down lightly to ensure it sticks.

Bake muffins for about 20 minutes or until a toothpick inserted does not come out with wet batter clinging to it.

Cool in pan ten minutes, then turn muffins out and finish cooling on a wire rack