Preheat your oven to 350°F and grease a 9x5 inch loaf pan with butter or cooking spray, paying special attention to the corners and edges. While the oven preheats, mash your very ripe bananas in a large bowl until mostly smooth with just a few small lumps remaining—this takes about 2-3 minutes and contributes to the bread's natural sweetness and moist texture.

Add the eggs, Greek yogurt, melted coconut oil, almond milk, maple syrup, and vanilla to the mashed bananas. Blend everything together for about 15 seconds using an immersion blender or whisk until the mixture is smooth and well combined. This wet base should be creamy and uniform, with no streaks of yogurt visible. I find that blending rather than whisking helps incorporate the yogurt smoothly and creates a more tender crumb in the final bread.

In a separate medium bowl, whisk together the pastry flour, protein powder, baking powder, cinnamon, salt, and nutmeg until evenly distributed. This ensures the leavening and spices are spread throughout the flour rather than clumping in one spot, which guarantees consistent flavor and rise in every slice. I like to whisk for about 30 seconds to break up any lumps in the protein powder.

Pour the dry ingredient mixture from Step 3 into the wet ingredient mixture from Step 2 and fold together gently using a spatula until just combined—stop folding as soon as no streaks of flour remain. Overmixing at this stage can develop gluten and make the bread tough, so aim for a slightly lumpy batter. Pour the batter into your prepared loaf pan and smooth the top with a spatula.

Bake uncovered for 30 minutes at 350°F until the top is light golden and a toothpick inserted near the center comes out with a few moist crumbs. Then cover the top loosely with aluminum foil to prevent over-browning and bake for an additional 20-25 minutes until a toothpick inserted into the very center comes out clean or with just one or two tiny crumbs. The two-stage baking method allows the edges to set while the center stays moist and tender.

Remove the bread from the oven and let it cool in the pan for 15 minutes—this allows the structure to set so it won't crumble when turned out. Turn the bread out onto a wire cooling rack and let it cool for at least 30 minutes before slicing. This cooling time is crucial because the crumb continues to set as it cools, so slicing too early will result in a gummy texture.