Preheat oven to 350 degrees.
Grease your muffin tin with butter or oil. I don't recommend paper liners because most paper liners will stick to the batter while it bakes, unless you use very high quality liners.
Combine the mashed bananas, vanilla extract, melted butter, beaten eggs, and unsweetened applesauce in a small bowl.
2 cups mashed ripe bananas, 1 teaspoon vanilla extract, 2 ½ tablespoons unsalted melted butter, 2 ½ tablespoons unsweetened applesauce, 2 eggs beaten
In a separate large mixing bowl, combine the flour, protein powder, sweetener, salt, baking soda, and cinnamon.
2 cups all purpose flour, 1 teaspoon ground cinnamon, ½ cup sweetener or sugar, ½ teaspoon salt, 1 teaspoon baking soda, 93 grams protein powder
Add the wet ingredients (banana mixture) to the dry ingredients (flour mixture). Mix with a silicone or wooden spoon. The mixture will appear dry because of the protein powder. Add in 2 tablespoons of water here to incorporate moisture. Add additional water if the mixture still appears dry.
2 tablespoons water
Stir to combine. Don't overmix. Ensure the flour is incorporated, but the mix should be lumpy. If you overmix, this will impact the texture of the muffins. They will be tough.
Fold in the chocolate chips.
½ cup chocolate chips
Pour the batter into muffin tins about ¾th of the way up.
Bake for 18-25 minutes until a toothpick returns clean.
Cool before serving.