Tiramisu Layer Cake

This tiramisu layer cake features moist chocolate cake, a quick coffee soak, and creamy mascarpone buttercream.

Course Dessert

Cuisine American, Italian

Keyword buttercream, cake, chocolate, coffee, dessert, espresso, layer cake, mascarpone, nut-free, rum, swiss meringue buttercream, tiramisu, tiramisu layer cake, vegetarian

Prep Time 1 hour

Cook Time 30 minutes

Total Time 1 hour 30 minutes

Servings 16 people

Calories 497 kcal

Ingredients

Chocolate Cake

2 ½ cups all-purpose flour
1 cup unsweetened cocoa powder
2 ½ teaspoons baking powder
¾ teaspoon baking soda
1 teaspoon kosher salt
½ cup + 2 tablespoons canola oil
1 ⅓ cups granulated sugar
2 eggs + 1 egg yolk room temperature
2 teaspoons vanilla extract
1 ½ cups whole milk room temperature
1 cup hot strong-brewed coffee

Rum-Espresso Soak

2 teaspoons instant espresso powder
¼ cup dark rum

Mascarpone Buttercream

½ cup + 2 tablespoons egg whites about 5 egg whites
1 ¼ cups granulated sugar
3 sticks unsalted butter room temperature, cubed
¾ cup mascarpone softened
1 tablespoon dark rum
1 teaspoon vanilla extract

Instructions

Chocolate Cake

In a medium bowl, whisk the dry ingredients.
Beat the oil and sugar until combined. Add the eggs and vanilla; beat until combined. Add the flour mixture in three batches, alternating with the milk, beginning and ending with the flour mixture. Stream in the coffee, then mix until combined.
Divide between three 8” round cake pans and bake at 350F for 25-28 minutes, or until a skewer inserted in the center comes out with moist crumbs.
Cool in the pans for 10-15 minutes, then turn out onto a wire rack to cool completely.

Rum-Espresso Soak

Combine the espresso and rum until the espresso dissolves.

Mascarpone Buttercream

Whisk the egg whites and sugar in a heatproof bowl. Place over a double boiler. Heat until the sugar is dissolved and the mixture is hot to the touch.
Whisk until medium-stiff peaks form and the bowl should be cool to the touch. Add the butter, a few cubes at a time, with a paddle attachment. Once all the butter incorporated, turn the mixer to medium-high and beat until the buttercream is silky smooth. Add the mascarpone, rum, and vanilla; mix until combined.
Brush the cakes with rum-espresso soak. Put a layer on a turntable or serving dish top side up, and spread ½ cup buttercream with an offset spatula. Top with the last cake and frost with the remaining buttercream. Finish with chocolate curls, if desired.

Recipe Notes

Adapted very slightly from The Vanilla Bean Blog (but really from Tessa Huff’s Layered).

Note that the cake pictured here was made in 6.5" cake pans, while this recipe is meant for 8" pans. If you want to make a 6.5" cake, you can half the (whole) recipe and bake the cakes in two 6.5" pans for 30-35 minutes.

You can adjust the amounts of rum in the rum-espresso soak and the buttercream depending on how much you like rum. I'd caution against increasing it too much though, especially in the buttercream; you don't want the buttercream to get too loose.