Preheat oven to 180°C (350° F).
Mash the bananas with a fork. In a bowl, whisk eggs, mashed bananas, oat milk, vanilla extract, maple syrup and peanut butter.
Add oat flour, baking powder and mix until well-combined. Add chocolate chips (leave some for decoration) and mix.
Pour batter into greased muffin tin (or use muffin liners). Decorate with the rest of chocolate chips.
Bake for 20-22 minutes. Remove from oven, let cool completely and store for up to 6 days.
Tip: warm the muffins for few minutes in the oven each time before consuming for a fresher texture