This chocolate cake with marshmallow frosting makes everyone happy wherever it goes! A super-simple yet very elegant dark chocolate cake is filled with caramel and topped with meringue frosting. A hint of orange blossom in the caramel is special. Torch the beautiful white peaks and valleys on your cake for a toasty, s’mores-like effect, one I just can’t get enough of.

It’s no secret around here that I have a thing for the showstopper cake. I love to see them, eat them, and of course, bake them. I’m certain that my adoration (giving way to heart palpitations; i.e., passion) is rooted in nostalgia, and family cake DNA. Grandma Abowd, Mom’s mother, could do anything at all that she tried her hand at. That she put her hand to cake baking and decorating, among many many many other things, has always excited and inspired me.

This dark chocolate cake with marshmallow frosting dazzles every eye and every eater, too. It is similar to my Double Chocolate Cake Recipe, and it’s a little like s’mores but with elegance, beauty, all wrapped up in a special-occasion cake.

Ingredients

Cake:

• Unbleached, all-purpose flour
• Dutch Process cocoa powder (dutch processed cocoa powder is preferred over natural cocoa powder because of the deep, dark color and richness it provides)
• Granulated sugar
• Baking soda
• Baking powder
• Kosher salt (table salt is fine, just reduce by 1/2 teaspoon)
• Buttermilk. If you don’t have any, make it by squeezing a couple teaspoons lemon juice into the milk. Alternatively, substitute with sour cream.
• Water
• Neutral oil, such as canola, vegetable, or safflower
• Large eggs
• Vanilla extract
• Espresso powder

Caramel filling:

Purchased caramel sauce works fine here too! Substitute about 2 cups prepared caramel sauce.

• Granulated sugar
• Light corn syrup
• Water
• Heavy cream
• Unsalted butter, cut in 8 pieces
• Vanilla extract
• Orange blossom water (optional)
• Kosher salt

Marshmallow frosting:

• 6 egg whites
• 1 cup granulated sugar
• 1/4 teaspoon cream of tartar
• 1/8 teaspoon kosher salt
• 1/2 teaspoon vanilla extract

How to Make Chocolate Cake with Marshmallow Frosting

Step 1: Make the chocolate cake.

• Sift flour and dark cocoa into a large bowl. Whisk in sugar, baking soda, baking powder, and salt. Whisk buttermilk, water, oil, eggs, vanilla and espresso powder together in a second bowl or large measuring cup. Whisk buttermilk mixture into the dry ingredients until a smooth batter forms. Divide batter evenly between two greased, parchment lined pans.
• Bake the cake at 325°F until a toothpick inserted in center comes out clean, 22 to 28 minutes, switching and rotating pans halfway through baking. Let the cakes cool in pans on wire rack for 15 minutes. Remove cakes from pans, discarding parchment, and cool completely.

Step 2: Make the Filling

• Combine sugar, corn syrup, and water in medium saucepan. Bring to boil over medium-high heat and cook, without stirring, until mixture is amber colored, 8 to 10 minutes. Reduce heat to low and continue to cook until dark amber, 2 to 5 minutes longer. (Caramel will register between 375 and 380°F).
• Off heat, carefully stir in cream, butter, vanilla, orange blossom water, and salt (mixture will bubble and steam). Return saucepan to medium heat and cook, stirring frequently, until smooth and caramel reaches 240 to 245°F, 3 to 5 minutes. Carefully transfer caramel to an 8-pan lined with parchment with an overhang, and let cool until just warm to touch, 20 to 30 minutes.

Step 3: Make the Marshmallow Frosting

• In the bowl of a stand mixer, stir together the egg whites, sugar, cream of tartar, and salt (I use the whisk attachment to stir). Set the bowl over a saucepan of simmering water, making sure that the bowl has some clearance above the water (we’re cooking very gently with the residual or steam heat here). Heat, stirring frequently, until the mixture reaches 160°F, about 8 minutes. 
• Transfer the whites to the stand mixer with the wire whisk attached. Beat, starting slow and increasing the speed steadily, until the mixer is on full. Whip until the stiff, glossy peaks form, 5 to 7 minutes. Stir in the vanilla and beat briefly.

Step 4: Assembly

• Use a long serrated knife to score 1 horizontal line around sides of each cake layer; then, following scored lines, cut each layer into 2 even layers to make 4 total layers.
• Using rubber spatula or large spoon, transfer 1/3 of caramel to center of 1 cake layer and use small offset spatula to spread over the surface, leaving 1/2-inch border around edge. Repeat with remaining caramel and 2 of remaining cake layers. (Three of your cake layers should be topped with caramel.)
• Line edges of a cake stand or platter with 4 strips of parchment to keep the cake platter clean. Place 1 caramel-covered cake layer on platter. Top with second caramel-covered layer. Repeat with third caramel-covered layer and top with final layer. Now you can cover and refrigerate the cake for up to one day.
• Spread the cake with marshmallow frosting thickly and evenly over sides and top of cake, making peaks and valleys with an offset spatula or the back of a spoon. Take care not to get chocolate crumbs in the beautiful white meringue. 
• I highly recommend toasting the marshmallow! Lightly skim the surface with a culinary torch.
• Carefully remove parchment strips. Leave the cake out at room temperature until serving, same (special) day.

Make-ahead instructions

To make this cake in advance, bake the cake layers, wrap them tightly in plastic, and refrigerate for up to one day or freeze, wrapped and in an airtight container, for up to 3 months.

Remember that the marshmallow frosting should not be made in advance. Make it and assemble the cake on the day it is to be served.

Storage

The cake can sit, covered, on the counter for up to one day. The frosting may harden on the exterior a bit, but it is still edible and good the next day.