Preheat the oven to 350 degrees F (175 degrees C). Line 10 muffin cups with paper liners.
Blend bananas, eggs, coconut flour, stevia, baking powder, and salt together in a bowl with a whisk or a fork. Stir in chocolate chips.
Pour mixture evenly between the prepared muffin cups, filling each about 1/2 inch from the top as these muffins won't rise as much as others.
Bake in the preheated oven until a toothpick inserted into the center of a muffin comes out clean, about 25 minutes. Cool for 5 minutes and transfer to a paper towel-lined plate; the moisture from the bananas will leak through the liners a little and this is normal.