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Cake on a cake stand with a chocolate drip and marshmallows on it.

Hot Cocoa Cake with Marshmallow Buttercream

4.98 from 42 votes
Dark chocolate cake layers with a light and fluffy marshmallow buttercream and chocolate ganache.
Prep Time 1 hour

Ingredients

FOR DARK CHOCOLATE CAKE

  • 2 cups (240 g) all-purpose flour
  • 1 3/4 cups (350 g) granulated sugar
  • 3/4 cup (88.5 g) dark cocoa powder, I use Extra Brute Cacao Barry
  • 2 teaspoons (8 g) baking soda
  • 1 teaspoon (6 g) salt
  • 3/4 teaspoon (3 g) baking powder
  • 3 eggs, room temperature
  • 1 cup (240 g) buttermilk, room temperature
  • 1 cup (236.6 g) hot water
  • 1/2 cup (109 g) vegetable oil
  • 1 tablespoon (4.2 g) pure vanilla extract

FOR THE BUTTERCREAM

  • 2 cups (452 g) unsalted butter, slightly chilled
  • 6 cups (750 g) powdered sugar, measured and then sifted
  • 12 ounces marshmallow cream, store bought like THIS
  • 3 ounces cream cheese
  • 1 teaspoon (4.2 g) pure vanilla extract
  • 1/4 teaspoon (1.5 g) salt

For the Ganache/Drip

  • 1/2 cup (85 g) dark chocolate chips
  • 1/2 cup (120 g) heavy whipping cream

Instructions

FOR THE CHOCOLATE CAKE

  • Preheat the oven to 325 degrees F. Prepare three 8-inch round cake pans by spraying the bottom and sides with nonstick spray, lining the bottom with parchment paper, and spraying the parchment paper. Set aside.
  • In a bowl of electric mixer, stir together all of the dry ingredients.
  • Combine eggs, buttermilk, water, oil and vanilla in a measuring cup and lightly beat with a fork.
  • With the mixer on low, add wet ingredients to the dry ingredients. Mix on low until the dry ingredients are incorporated, about 30 to 60 seconds. The batter will be thin. Scrape sides and mix on low for another 30 seconds. Divide batter evenly among prepared pans, about 15 to 16 ounces in each 8-inch pan.
  • Bake for 23 to 27 minutes (you may need more time depending on your oven), until toothpick comes out with just a few moist crumbs on it. Cool on wire racks for 10-15 minutes, then gently invert onto racks until cooled completely.
  • When cakes are completely cooled, I like to wrap each cake layer individually with plastic wrap and stick it in the refrigerator or freezer until I’m ready to frost. The cake will be easier to work with if it’s cooled a bit. If I’m making the cake a day or two before I actually need to frost it, I put it in the freezer to ensure freshness. If I’m frosting same-day, I still put the cakes in the freezer for an hour or so.

FOR THE BUTTERCREAM:

  • In the bowl of a stand mixer fitted with a paddle attachment, beat the butter and cream cheese for about 2 minutes.
  • With the mixer on low speed, gradually add the sifted powdered sugar, one cup at a time, mixing a little in between each addition.
  • With mixer on medium speed, add the marshmallow cream, followed by the vanilla and salt.
  • Turn the mixer to medium-high speed and beat for an additional 3 to 5 minutes. The frosting will become lighter in color and texture.
  • Before spreading on your cake, spend a couple minutes mixing the buttercream by hand with a wooden spoon to push out the air pockets.

For the Ganache/Drip

  • In a microwave safe bowl, heat the cream and the chocolate chips together in 30 second intervals, until the chocolate is melted and smooth when you stir.
  • The mixture will thicken as it cools. Make sure it cools completely before using between the layers. If the mixture is too thick for the drip, just heat it again for about 10 seconds.

ASSEMBLY

  • Place the first cake layer, top side up, on a cake board or cake stand. Using an offset icing spatula, sread about 1 cup of buttercream on top. Make sure to get eye level with the cake to ensure the frosting is spread evenly over the cake. Drizzle chocolate ganache on top of the buttercream.
  • Repeat this step until you get to the final cake layer, which you will lay top side down.
  • Apply a thin coat of buttercream around the entire cake to lock in the crumbs. Freeze for about 10 minutes.
  • After the crumb coat is set, continue frosting and decorating the cake.
Author: Courtney Rich
Course: Dessert
Cuisine: Cake
Keyword: Black and White Cake, Chocolate Cake, hot chocolate cake, hot cocoa cake, marshmallow, Marshmallow buttercream