“The rockiest roads lead to the highest peaks.”
Now you know the secret behind the homemade marshmallows! They were made for this out-of-this-world cake.
My Rocky Road cake features dense, dark layers of my favorite chocolate cake, silky chocolate buttercream, homemade marshmallows, toasted almonds, and a dark chocolate drizzle to finish.
This is not a quick bake. It’s an over-the-top celebration cake best reserved for special occasions—unless you’re a baker or obsessed with baking, in which case coworkers might receive a four-layer cake on a random Tuesday.
If you want to simplify: bake a single cake layer, make half the buttercream (or skip buttercream and use ganache), and use store-bought marshmallows. It’s simpler and still delicious.
Below I share the assembly steps. The individual recipes and detailed picture tutorials are available in the printable section.
Let’s get started:
If you are making marshmallows, prepare them the day before or earlier and cut into squares.
Bake your chocolate cakes, wrap them in plastic, and chill in the refrigerator for at least 2–3 hours. Once cold, slice each cake horizontally into two even layers using a long serrated knife.
Toast the almonds at 350°F (180°C) for 8–10 minutes or toast them on the stovetop. Allow to cool, then coarsely chop.
Prepare your chocolate buttercream and reserve about 1/4 cup in a piping bag.
Make the ganache when you are ready to assemble the cake. Fill a piping bag and cut a small opening for controlled drizzle.
Place the best-looking cake layer on your cake board or plate with the cut side up. The cake is moist, so syrup is optional; I didn’t use any.
Spread roughly 1/4 cup of buttercream over the cake layer.
Pipe a ring of buttercream just inside the edge to form a frosting “dam.” This keeps the nuts and marshmallows from migrating into the outer frosting.
Sprinkle chopped toasted almonds and marshmallow pieces evenly but sparingly—this cake has three filling layers. Drizzle some ganache from the piping bag over the filling.
Top with the next cake layer and repeat the filling process for each layer. Reserve the second-best cake layer for the top and place it cut-side down.
Spread another 1/4 to 1/2 cup of buttercream on top and smooth with a spatula. Apply a thin crumb coat to the sides to trap crumbs—perfection isn’t necessary, just enough to hold crumbs in place. Chill the cake in the freezer for 20 minutes.
Finish as you like. I smoothed the buttercream, added a ganache drip, and piled remaining toasted almonds and marshmallows on top.
Tips and notes:
- Keep the cake refrigerated and bring to room temperature about 30 minutes before serving.
- The buttercream quantity used was just enough for a simple covering. For decorative piping, double or increase the recipe by 1.5×.
- To simplify the cake: 1) Bake a half recipe of cake, pour ganache on top, sprinkle nuts and marshmallows, and add another drizzle of ganache. 2) Use store-bought marshmallows. 3) Choose either chocolate buttercream or ganache, not both. 4) Substitute whipped cream for the buttercream and ganache for a lighter finish.
This cake is extravagantly rewarding: super-moist chocolate layers, two kinds of chocolate frosting, crunchy toasted nuts, and chewy marshmallow bites. It’s easier to make than it looks—though the downside is that after all the effort, the cake will likely disappear within minutes of the first slice!