Mix your softened butter, peanut butter, and heavy cream together.
Add your coconut flour, flax seed meal, baking powder/soda, and erythritol in the mixture and mix well.
Add your egg and mix well until batter is thick and creamy, but pliable.
Make balls with the dough and lay them on a silicon baking sheet.
Press the balls down with your fingers and add a design on the top if you'd like.
Bake for 15 minutes until they are only a little crisp on the outside. You want the inside to stay soft.
Sprinkle with Erythritol as they come out the oven. They will take some time to cool, you can speed up the process by putting them in the refrigerator.