Preheat oven to 325°F (160°C). Grease and flour two 8-inch round cake pans with coconut flour, tapping out excess. Line bottoms with parchment paper.

In a large bowl, whisk together coconut flour, granular sweetener, whey protein powder, shredded coconut, baking powder, and salt until no lumps remain.

In a separate medium bowl, whisk together melted butter, egg whites, whole eggs, and coconut extract until well combined and smooth.

Pour the wet ingredients into the dry ingredients and mix with a whisk until just combined. Do not overmix; the batter will be thick.

Divide the batter evenly between the prepared cake pans, smoothing the tops with a spatula. Bake for 25-30 minutes, or until a wooden skewer inserted into the center comes out clean and the cake is lightly golden.

Let the cakes cool in the pans for 10 minutes before inverting them onto a wire rack to cool completely. Once cool, frost with your favorite keto-friendly coconut frosting and garnish with extra shredded coconut if desired.