This Tiramisu Layer Cake is light, soft, moist, and soaked with coffee liqueur syrup and filled with irresistible mascarpone frosting between each layer. No raw eggs and the strong coffee flavor is guaranteed.
Combine sugar, instant coffee, and hot water in a small bowl. Stir until the sugar is dissolved. Stir in the liquor if using. Cool completely before using.
Mascarpone Frosting
In a large bowl using a handheld or stand mixer fitted with a whisk attachment, combine the heavy whipping cream, confectioners' sugar, and vanilla extract. Whip until the mixture starts to thicken and stiff peaks form. Set aside.
In a large bowl, soften the mascarpone cheese. Add half of the whipped cream and whip on low speed until well incorporated and looks lump-free. Add the remaining whipped cream and whip on high speed until stiff peak. Refrigerate the frosting until using it.
Assemble
Cut the genoise cake horizontally into even 3-4 thin layers (I usually get 4 layers if my eggs are bigger)
Place the bottom cake layer on your cake stand or serving plate. Brush the coffee syrup on top generously. Make sure the sides and all the surfaces are covered.
Spread the mascarpone frosting thinly and evenly. Level the top with a spatula to make it even.
Place another cake layer on top. Then, continue brushing the coffee syrup and spreading the frosting until you place the top layer.
Brush the coffee syrup on top generously. Lightly cover the top and sides of the cake with more cream.
Topping
Add whipped cream to the remaining mascarpone frosting. Pipe it on top of the cake for decoration.
Dust the top with cocoa powder.
Tiramisu Layer Cake is best refrigerated for at least 8-12 hours before serving to allow the flavors to blend.
Notes
Liqueur options for Tiramisu Layer Cake: Marsala wine, dark rum, brandy, coffee-flavored liqueur like Kahlua, or almond liqueur like Amaretto.Use decaf coffee for caffeine-free tiramisu cake.