Mix eggs and erythritol to make meringue.
Add almond flour and baking powder to complete the batter.
Bake the batter in the oven to make the keto sponge layer.
Brew coffee and soak the sponge sheet.
Make cream by mixing cream cheese, mascarpone cheese, and erythritol.
Layer the cream on the keto sponge and stack the layers.
Dust cocoa powder on the final layer to finish.