Low Carb Hot Cocoa Cake

My grown daughter had a birthday last week and I quickly volunteered to make her a birthday cake. I had seen a similar cake online (see the inspiration for this recipe here), but it is made with flour and lots of sugar, and I couldn’t resist making it over using low carb, sugar free and gluten free ingredients. The results were absolutely spectacular! My family has declared that this cake may be the very best to come out of my keto/low carb kitchen, so far! 

The puffs of marshmallow fluff on the top calls for a different sugar alternative called allulose  As much as I dislike purchasing another product to try and fit into my already overstuffed keto baking drawer, in this case, allulose is the best sugar alternative for the job. It won’t recrystalize upon cooling, like erythritol can, leaving the marshmallow puffs soft and pillowy. You can leave them off and still make the best low carb chocolate cake ever!

Low Carb Hot Cocoa Cake

Makes 12 servings

Cake Ingredients:

96 grams coconut flour (about 3/4 cups + 2 tablespoons)

3/4 cup granulated erythritol sweetener 

1/3 cup unsweetened dark cocoa powder

1 tablespoon baking powder

1/2 teaspoon xanthan gum

1/4 teaspoon salt

6 large eggs, room temperature 

1/2 cup unsalted butter, melted and cooled

1/2 cup brewed coffee, cooled to room temperature (regular or decaf is fine)

2 teaspoons vanilla extract (or 1 tsp vanilla and 1 tsp chocolate extract)

Chocolate Frosting:

3 ounces unsweetened 100% cacao baker’s chocolate, chopped

3/4 tablespoon coconut oil (I used refined)

3 tablespoons unsalted butter, room temperature 

6 ounces cream cheese, room temperature 

12 ounces mascarpone cheese, room temperature 

1 cup powdered erythritol sweetener 

3 tablespoons unsweetened cocoa powder 

3/4 teaspoon vanilla extract 

3-4 tablespoons heavy cream, room temperature (or enough to reach desired spreading consistency)

Whipped Marshmallow Topping:

3/4 cup allulose sweetener 

1/3 cup water

1 large egg white

1/2 teaspoon vanilla extract 

A tiny pinch of salt

To Make the Cake:

1. Preheat your oven to 325 degrees Fahrenheit. Prepare two 8” or three 6” baking pans by spraying with non-stick cooking spray and line the bottoms with parchment paper. Spray the parchment paper; set aside.

2. Whisk together the first six ingredients (coconut flour through salt) in a medium bowl. (If you’re not able to weight the coconut flour, use a very light scooping and leveling method to measure.) Set aside.

3. In a large bowl and with an electric mixer, beat the eggs until light, lemon yellow in color and the volume has increased, about 3-5 minutes. Try to beat as much air as possible into the eggs. (If you have standing mixer, you can use a whisk attachment to make this easier, but remove it and replace with your paddle attachment before adding the remaining ingredients, so as not to deflate the eggs too much.) Add the melted and cooled butter, coffee and extract, mixing on low only to combine.

4. Add the dry ingredients all at once and mix on low to medium just until the dry ingredients are incorporated. Divide the batter evenly between the prepared baking pans and spread to the edges and level the batter using an offset spatula or back of a spoon. Bake for 30 minutes or until the tops are just firm to the touch and a toothpick in the center comes out clean. (If using 6-inch pans, check after 25 minutes.)

5. Remove from the oven and allow the cake to cool in their pans for about 10-15 minutes before turning them out on a wire rack to cool completely.

To Make the Chocolate Frosting:

6. In a medium microwave-safe bowl, combine the chopped baking chocolate and coconut oil. Microwave in 15 second intervals to melt the chocolate. Allow to sit for a few minutes before stirring until smooth. (You may also place the chocolate in a heat-proof bowl over barely simmering water to melt.) Set aside to cool to lukewarm.

7. In a large bowl with an electric mixer, beat the butter, cream cheese and mascarpone cheese together until well combined and no lumps remain. (I used my paddle attachment to do this.) Beat in the powdered erythritol and cocoa powder until blended. Add the melted chocolate and extract and beat until smooth. Add 1 tablespoon of the heavy cream at a time until the desired spreading consistency is reached.

To Make the Marshmallow Topping: (This can be made a day ahead and refrigerated. Bring to room temperature before decorating the cake.)

8. To a medium saucepan, add the allulose and water and very gently stir to combine. (The allulose will not dissolve at this point.) If any allulose has gotten on the sides of the pan, use a wet pastry brush to wipe down the sides.

9. Over medium-low heat, bring the allulose and water mixture up to 260 degrees Fahrenheit. DO NOT STIR. Bring the mixture up to temperature slowly, it may take 15 minutes or so. If you see it starting to turn brown, reduce the temperature, you don’t want the allulose to burn. 

10. Using an electric or standing mixer, whip the egg white with a tiny pinch of salt until foamy and soft peaks form. Slowly, and very carefully, while the mixer is on low, pour the hot allulose mixture into the egg white. (This mixture is VERY HOT, so use a potholder and stand away from the mixing bowl as you pour so the hot liquid doesn’t splash on you.) 

11. Turn the mixer to high, add the vanilla extract and whip for 5-6 minutes or until the marshmallow fluff is glossy and holds a stiff peak.

12. Assemble your cake by placing one layer of your cooled cake on a plate, spread with a generous amount of chocolate frosting, top with the second layer and then spread frosting on the top and sides. (To achieve the banded look in the photo, I used a design scraping tool to create a scalloped edge, but this is optional. See photo below of the tool set by Wilton for adding texture to cakes.) Finally, dollop mounds of the marshmallow on the top, creating puffs. You can do this with a large spoon or place the fluff into a piping or gallon plastic bag and snip off the end and pipe the marshmallow. Dust with cocoa powder.

13. This cake should be stored in the refrigerator. Remove and allow the cake to sit at room temperature for 30-45 minutes before slicing and serving.

Nutritional Information per serving (1/12th of cake): 333 calories, 9.3 g carbohydrate (4.6 g dietary fiber, 1.2 g sugars), 29.3 g total fat (18.4 g saturated fat, 0 g trans fat), 152 mg cholesterol, 249 mg sodium, 111.4 mg calcium, 78 mg potassium, 2 mg iron, 170 IU Vit A, 8.4 g protein. Net carbs per serving: 4.7 grams

Cake photos and recipe by Kathy Sheehan, copyright 2021

All rights reserved. Please do not duplicate without the author’s permission.