Preheat your oven to 3500F (1750C) and grease and flour a 9x13 inch baking pan. Squeeze any excess moisture from the grated zucchini using a paper towel or clean kitchen towel. Set aside.

In a large bowl, whisk together the almond flour, granular sweetener, Dutch process cocoa powder, coconut flour, whey protein powder, baking powder, and salt until well combined.

In a separate medium bowl, whisk the eggs until light and frothy. Stir in the melted butter and the squeezed zucchini.

Pour the wet ingredients into the dry ingredients. Mix with a spatula until just combined. Do not overmix.

Spread the batter evenly into the prepared baking pan. Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean.

Let the cake cool completely in the pan before slicing and serving. This cake is delicious on its own or with a keto-friendly cream cheese frosting.