Preheat your oven to 350°F (175°C). Grease a 9×5-inch loaf pan or line it with parchment paper.

Mash the bananas in a large mixing bowl until smooth.

Whisk in the eggs, Greek yogurt, honey, and vanilla extract until well combined.

Add the oat flour, protein powder, baking soda, baking powder, cinnamon, and salt. Stir just until no dry flour remains.

Fold in any optional mix-ins if desired.

Pour the batter into the prepared loaf pan and smooth the top.

Bake for 45–55 minutes, or until a toothpick inserted into the center comes out clean.

Allow the bread to cool in the pan for 10 minutes before transferring it to a wire rack.