Measure out the butter and put it inside the mug you will be using. This should be at least a 12 oz mug.

Microwave the butter for 20-25 seconds until it is mostly melted and hot. Add the sweetener to the melted butter.

Add the cocoa powder to the butter.

Add the coconut flour, almond flour, baking powder, and vanilla.

Don't forget the egg! It will help the cake rise.

Mix the ingredients well, until everything is combined and there's as few lumps as you can get. If you're going to make 2 servings, this is the point where you would measure the batter out into 2 mugs or 2 ramekins.

Microwave the cake for 60-75 seconds. It takes 75 seconds in my microwave. If you are making 2 servings, probably 50-60 seconds would do the best - I never make 2 servings because I'm greedy.

While you're waiting for the cake to cook, whip some cream in a mixing bowl. (Optional)

Let the cake cool for a moment and spoon on the whipped cream. (Optional)