Add 1 tablespoon of butter to a 6"cast-iron skillet and place in the oven while mixing the rest of the ingredients. (Does not have to be preheated.)
Combine coconut oil, a tablespoon of butter, and cream cheese. Either melt on the stove or microwave.
Combine flour, cocoa powder, and baking powder in a separate bowl. Whisk until combined.
Add eggs, coconut milk, sweetener, and vanilla to the coconut oil, butter, and cream cheese mixture.
Beat on low/medium for 1 minute or until smooth.
Add flour, cocoa powder, and baking powder mixture to other ingredients and beat until combined.
Remove the cast-iron skillet from the oven and swirl the butter around to grease the bottom/sides of the skillet.
Pour batter into the skillet and bake at 350 degrees for 15-17 minutes. Insert a knife in the middle of the cake to test doneness. Do not overbake.
Serve with homemade whipped topping and shaved unsweetened chocolate.
Notes
The nutritional information for this recipe was calculated based on eight servings. The sugar alcohols from the keto-friendly sweetener are not included in the nutritional information since most subtract to calculate net carbs.