Begin by preheating your oven to 350°F (175°C). Generously coat an 8x4-inch loaf pan with non-stick spray (or line with greased parchment). Note: A 9x5-inch pan works but reduces baking time.
Dry Mix
In a large bowl, combine coconut flour, unsweetened shredded coconut, keto sweetener, protein powder, baking powder, and salt. Whisk thoroughly to eliminate clumps.
Wet Ingredients
Pour melted coconut oil, egg whites, whole eggs, coconut extract, and vanilla into the dry mix. Stir until fully incorporated. Gradually add water, mixing until the batter is smooth and thick.
Blueberries
Gently fold ¾ cup of blueberries into the batter. Transfer to the prepared pan, spreading evenly. Scatter remaining berries over the top for a burst of flavor.
Bake & Cool
Bake 50–60 minutes until golden, springy to the touch, and a toothpick inserted comes out clean. Let cool in the pan for 30 minutes, then transfer to a wire rack to cool completely before slicing.