In a large bowl, combine coconut flour, ground almonds, hazelnuts, cocoa powder, sweetener, and baking powder. Microwave butter and add in the mixture. Mix with an electric mixer.
Add one egg at a time and whisk.
In a silicone donut pan add one tablespoon of the mixture. I got 11 small donuts.
Bake for 15 minutes.
Make your topping. Combine heavy cream, cocoa powder, and erythritol. Dip the top of each donut.