Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.
Whisk together the oat flour, protein powder, monk fruit sweetener, and baking powder in a large mixing bowl.
Add the Greek yogurt and vanilla extract to the dry mixture and stir until a stiff dough forms.
Add almond milk only if the dough is too crumbly to hold together.
Fold in the mini chocolate chips until evenly distributed.
Divide the dough into 12 equal balls and place them on the prepared baking sheet.
Flatten each ball with the back of a spoon or your palm as these cookies do not spread during baking.
Bake for 8 to 10 minutes until the edges are just firm to the touch.
Remove from the oven and allow to cool on the sheet for 5 minutes to set before moving to a wire rack.