Preheat oven to 180°C (350°F). Line a small loaf tin with baking paper or lightly grease it.
Mash bananas until smooth.
Add yoghurt and eggs to the bananas and mix until combined.
Add oat flour, whey protein, salt, baking powder, and baking soda. Mix just until combined. Don’t overmix!
Fold in chocolate chips or other mix-ins.
Pour batter into the loaf tin and bake for 40-50 minutes (timing depends on your tin and oven).It’s done when a toothpick comes out mostly clean. Remove from oven and cool for 10-12 minutes.