Preheat the oven to 190ºC (400ºF) and line a baking sheet with parchment paper.
In a large mixing bowl whisk the egg, the mashed banana (or applesauce) and nut butter until creamy. Add to the bowl granulated sweetener, cinnamon, vanilla extract and salt. Using a whisk or fork, stir the wet mixture for a couple of minutes until all is well combined.
Add rolled oats, almond flour, protein powder and baking powder to the wet mixture. Using a spatula or fork stir all ingredients together. Based on the protein powder used, you might need to adjust the dough with a pour of milk if it is too thick.
Fold in chocolate chips.
Refrigerate the oatmeal protein cookie dough for at least 10 minutes.
Scoop out 1/3 cup dough and shape 9 cookies. Transfer the protein cookies to parchment paper covered baking sheet, spacing cookies apart.
Bake oatmeal cookies in hot oven for 10 to 12 minutes – mine took 11 minutes – and let cool over a baking rack.