In a bowl, combine the flour, wheat bran, baking powder, baking soda and salt. Stir with a whisk.
Melt butter in a small skillet over medium heat. Cook for 1-2 minutes or until browned and fragrant. Combine butter, yogurt, sugar, vanilla, banana and egg in another bowl.
Add yogurt mixture into the flour mixture. Stir until just combined.
Spray a muffin tin with cooking spray. Divide batter evenly into 12 muffin cups.
Bake for 22 minutes or until a toothpick inserted into the center comes out clean. Let cool for 5 minutes in the pan. Remove from pan and let cool completely.