Swiss Roll
Ingredients
Buttercream Filling:
- 1⅔ cups powdered sugar
- ½ cup unsalted butter, at room temperature
- 2 tbsp chocolate or coffee-flavoured liqueur
- 1½ tbsp unsweetened cocoa powder
- 1 pinch salt
- (⅓ cup mascarpone cheese, optional)
Sponge Cake:
- 2 tbsp melted butter
- ½ cup unsweetened cocoa powder
- 2 tbsp all-purpose flour
- ½ tsp kosher salt
- 5 large eggs, at room temperature
- ⅔ cup white sugar
- ½ tsp vanilla
- 2 tbsp powdered sugar, or as needed
Ganache Frosting:
- 1 cup heavy cream, boiling-hot
- 1 (225g/8 ounce) package dark chocolate chips
Method
- To make the buttercream filling: Whip powdered sugar, butter, coffee-flavoured liqueur, cocoa powder, and salt together in the bowl of a stand mixer fitted with the whisk attachment on high speed.
- Transfer filling mixture to a separate bowl and add mascarpone cheese. Mix until combined; set aside. Clean and dry the stand mixer bowl.
- Preheat the oven to 200°C.
- Prepare a 13”x18” rimmed sheet pan for the sponge cake: Brush a little melted butter over the sheet pan, then line the pan with parchment paper, and brush remaining melted butter on top.
- Sift the cocoa powder, flour and salt, then whisk together in a bowl, making sure to break up any clumps.
- Place eggs in the clean bowl of your stand mixer. Add sugar and whip with the whisk attachment until fluffy, thick, and very light in color, 2 to 3 minutes.
- Add vanilla and ½ of the cocoa powder mixture; mix on low speed for a few seconds.
- Add remaining cocoa mixture and mix on low for a few seconds. Switch to high speed and mix until the mixture is moistened but not fully blended.
- Pull off the whisk attachment and use it to whisk the batter by hand until evenly blended.
- Pour batter onto the prepared sheet pan and spread out with a spatula, almost to the edges, but not quite. Tap the pan on the counter several times to remove any large air bubbles.
- Bake in the preheated oven until the top is dry and the edges start to pull away from the sides, 8 to 10 minutes.
- While the cake is baking, sift powdered sugar onto a clean kitchen towel to cover an area slightly larger than the sponge cake.
- Remove cake from the oven. Run a knife around the edges of the pan. Dust some powdered sugar over the top. Run a spatula under the parchment paper to make sure it's not stuck to the pan.
- Quickly flip the pan on top of the sugared area on the towel to invert the cake.
- Carefully remove the parchment paper, then sift more powdered sugar over the cake.
- Gently roll the cake up inside the towel; allow to cool in this position for 15 minutes.
- Carefully unroll the cooled cake. Dollop as much buttercream filling as you like on top, reserving some for later; spread to the edges.
- Roll cake up over the filling, using the towel to lift it if needed.
- Sprinkle more powdered sugar on top over the log, then wrap in plastic wrap. Refrigerate until firm, about 2 hours.
- To make the ganache frosting: Pour hot cream over chocolate chips in a bowl. Let sit for 1 minute, then whisk until chocolate is melted.
- Spread a layer of ganache all over the cake, except for the swirls on the ends. Refrigerate for 15 minutes to firm up the ganache.
- Dust with cocoa powder and powdered sugar before serving.
[!TIP] All of the buttercream filling may be a little bit too much. You can use ⅔ of the filling for this recipe, and save the rest for cupcakes. Or, if you have a favourite frosting or filling, it will work here. As long as you can slice it later, pretty much anything goes. You can also add a splash of milk to achieve a lighter, fluffier buttercream.