Preheat your oven to 400 degrees
Grease your muffin pans with butter or non stick cooking spray
In your mixing bowl, add your all-purpose flour, baking powder, salt, and granulated sugar. Stir until well combined. Set aside
In separate bowl, add your bran flakes and milk. Stir and let stand for about 2 minutes so your cereal softens up
Add your egg and oil to your bran flake mixture and beat until well combined
Gradually stir in your dry ingredient mixture until well combined
Pour muffin batter evenly into muffin pans
Bake in preheated oven for 23-25 minutes. Your muffins are done when they are golden brown
Carefully remove from oven and cool your muffins in the pan on a wire rack
Serve and enjoy!