First, prepare the flax egg by combining the ground flax with water. Set aside to thicken.
In a casserole dish or bowl, mash the bananas. Add the plant-based milk, vanilla extract, maple syrup and flax “egg”. Stir until combined.
Now, in a blender, add the oats. Blend until a fine flour is formed. Skip this step if using store-bought oat flour.
Into the bowl with the wet ingredients, add the flour and baking powder, and gently stir until a thick batter is formed. Fold in the mini chocolate chips until smooth.
Transfer to a muffin tray, and bake for 25 minutes, until a toothpick comes out clean. This will make approximately 12 muffins.