Melt the butter in a microwavable cup or ramekin, about 30 seconds. Swirl the butter to coat the cup.
Add the cream, egg, almond flour, cocoa powder, Swerve, vanilla, and baking powder. Whisk until well combined. Save a raspberry or two for garnish, if desired, and stir the rest into the cake batter. Microwave on full power for 90 seconds or until the cake is set.
Top with whipped cream and garnish with reserved berries, if desired.
Gluten Free Keto Cake in a Cup Recipe https://glutenfreeandmore.com/blog/2018/04/gluten-free-keto-cake-cup-recipe.html