Preheat the oven to 325°F (165°C) and grease an 8-inch baking dish.
In a mixing bowl, combine the cocoa powder with the Erythritol, almond flour, baking powder, and salt.
In another bowl, whisk the eggs with the coconut oil and vanilla extract.
Gradually combine the two mixtures together, whisking to get a smooth batter.
Pour into the prepared baking dish, and bake in the preheated oven for 20 minutes.
Allow to cool down, then slice and serve.