Preheat oven to 375 F (190 C). Line a 12-cup muffin pan with liners or spray with baking spray. Set aside.
Peel, slice, and mash bananas in a medium bowl. Set aside.
4 medium bananas
In a large mixing bowl, combine dry ingredients.
1 cup almond flour, 1 cup all-purpose flour, ⅔ cup vanilla whey protein powder, 2 teaspoons baking powder, ¼ teaspoon salt, ½ cup light brown sugar
Stir in banana, almond butter, and vanilla extract.
4 medium bananas, ½ cup almond butter, 1 teaspoon vanilla extract
Spoon batter into each cup of the prepared muffin pan, dividing evenly. There should be enough batter to fill each cup almost to the top.
Bake for 20 to 25 minutes, or until a skewer inserted into the center comes out clean. Remove pan from oven and set on a wire rack to cool for several minutes. Remove muffins from pan and allow to cool fully.