Preheat the oven to 350F.

Whisk together egg yolks, butter, heavy cream, baking powder and sweetener. Stir in the almond flour until fully combined.

In a stand mixer bowl, whisk the egg whites until soft peaks have formed. Take a spoonful of the egg whites and add them to the almond mixture to loosen them up. Then add the rest of the egg whites and gently fold the two mixtures together.

Pour the cake batter into a 9" springform cake tin, and bake for 13-15 minutes. Remove from the oven and leave to cool.

To make the frosting, add the almond butter and almond milk to a small saucepan, and gently heat. Stir until the two ingredients have mixed together. Spread all over the cooled cake.

Serve with a sprinkling of confectioner's Swerve, if desired.