Preheat your oven to 350°F (175°C).

Grease a 9-inch round cake pan with coconut oil or use parchment paper.

In a mixing bowl, combine the almond flour, cocoa powder, protein powder, erythritol, baking powder, and salt.

In another bowl, whisk together the eggs, melted coconut oil, and vanilla extract.

Add the wet ingredients to the dry ingredients and mix until just combined.

Pour the batter into the prepared cake pan and smooth the top.

Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted comes out clean.

Let the cake cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.

Once cooled, frost as desired or enjoy plain with a dusting of cocoa powder.