Preheat the oven to 350°F (175°C) and line a 9x5 inch loaf pan with parchment paper.
In a large mixing bowl, whisk together the mashed bananas, liquid egg whites, Greek yogurt, and vanilla extract until the mixture is homogenous.
In a separate bowl, sift together the vanilla whey protein powder, almond flour, baking soda, salt, and cinnamon to remove clumps.
Gently fold the dry ingredients into the wet ingredients using a spatula until just incorporated; do not overmix as it may toughen the texture.
Transfer the batter into the prepared loaf pan and smooth the surface with a spatula.
Bake for 45 to 50 minutes, or until an internal temperature of 200°F (93°C) is reached or a toothpick comes out clean.
Allow the bread to cool in the pan for 15 minutes before transferring to a wire rack to cool completely before slicing into 8 even portions.