Heat the oven to 350°F (175°C). Prepare a loaf pan by lining it with parchment paper or lightly coating it with cooking spray.
Add the oat flour, almond flour, vanilla protein powder, baking soda, baking powder, and sea salt to a large bowl. Stir until the dry mixture looks evenly blended.
In another bowl, combine the Greek yogurt, maple syrup, mashed bananas, eggs, and vanilla extract. Whisk until smooth and uniform.
Transfer the dry mixture into the bowl of wet ingredients. Stir gently until no dry pockets remain. Do not overmix to keep the texture soft.
Add the chocolate chips and fold them through the batter.
Spread the batter into the prepared loaf pan and smooth the top. Sprinkle extra chocolate chips over the surface if desired.
Bake for 55 to 65 minutes. The loaf is ready when a toothpick inserted in the center comes out mostly clean with a few moist crumbs. A small amount of moisture is fine since the bread continues to set while cooling. Check around the 30-minute mark and loosely cover with foil if the top is browning too quickly.