Chocolate Roll with Walnuts & Dulce de Leche Buttercream
For the Roll
1.5 cups sugar
1.5 cups sour cream
1 1/4 cups all purpose flour
1.5 tsp baking soda + 1 Tbsp vinegar
1/4 cup cocoa powder, sifted
3/4 cup ground or finely chopped walnuts
1/3 cup sugar
2 Tbsp water
1 Tbsp butter
2 sticks (225 grams) butter, unsalted, room temperature
1 cans dulce de leche
1 cup heavy cream (at least 33% fat content)
1/3 cup sugar
1 tsp vanilla extract
75 mls heavy cream
1/3 cup semi-sweet chocolate chips or chopped dark chocolate
2 tbsp corn syrup
Make the Roll:
- Preheat oven to 350F with the baking rack in the middle. Line a jelly roll pan (18 inches x12 inches) with parchment paper. Set aside
- Whith a stand mixer or a whisk whip together eggs & sugar until pale and fluffy, about 3-4 minutes. Add the sour cream and whip together for of couple seconds until incorporated. Add the flour, whisk to incorporate, then add the mixture of vinegar & the baking soda and whisk again. Sift in the cocoa powder and whisk one more time to create a smooth and lump free batter. Stop whisking as soon as the batter is smooth and lump free.
- Pour the batter onto a parchment lined baking sheet and smooth it out with a spatula. Bake for about 15 minutes or until a toothpick inserted in the middle comes out clean. Do not overbake or the cake will be dry and will be more prone to cracking as you roll it.
- Once baked, remove from the oven and run a knife along the inside edge of the cake pan. Sift some powdered sugar all over the top of the hot cake. Cover with a clean kitchen towel or a paper towel and roll the cake roll together with the parchment paper still attached to it into a tight roll. Allow to cool on a cooling rack completely.
Meanwhile work on the caramel frosting:
- Whisk 2 sticks of room temperature butter on high until white in color and fluffy, scraping down the sides of the bowl 2-3 times, about 4-5 minutes. Add dulce de leche in 2-3 additions whipping in between each addition to fully incorporate the dulce de leche. Once the last addition of dulce de leche has been made, only whip until it is incorporated. Overwhipping at this point will make the frosting run. Scrape down the sides to make sure there’s no stray lumps of butter. If you have added the dulce de leche and the frosting became too runny, refrigerate until firmer.
Also make the walnut filling:
- Combine the sugar and water and let the sugar melt. Add butter and stir until fully dissolved and incorporated. Allow the mixture to boil on medium heat until the caramel starts to change color, about 2-3 minutes. Add the walnuts, cook for another minute or two and remove from the heat. Allow the mixture to cool completely.
How to assemble the cake roll:
- Once the roll is completely cool, carefully unroll it and spread the frosting around into an even layer. Top with walnuts and spread them around to evenly coat. Now starting with narrow edge of the roll, unpeel the parchment paper off the cake as you roll it into a tight roll. Don’t worry if the cake roll cracks, it will be covered by cream later so the crack will not be visible. Use the same paper that was just peeled off to cover the roll and place in the freezer while you work on your whip cream and the ganache for decoration.
Make the Chantilly Cream:
- Combine the heavy whip cream, sugar and vanilla and whisk on high until fluffy and hold shape, about 3-4 minutes.
Make the Chocolate Ganache:
- Heat cream until very hot, or almost boiling and add chocolate chips. Let sit for 2-3 minutes to allow the chocolate to melt. Stir with a whisk or a spoon until glossy and homogeneous. Add corn syrup or glucose & stir until it’s well incorporated into the chocolate & smooth.
- Place the bowl or cup with ganache into another bowl or cup filled with cold water. Stir the chocolate slowly allowing it to cool to room temperature, or until it’s thick enough that it will form a drizzle when poured down the inside of the cup (about 10 minutes).
- Cover the sides of the serving platter with foil making sure that some of it will be about ½ inch under the roll. Transfer the roll to the platter. Cover the cake with a thin layer of cream. Remove the two pieces of foil that were along the long sides of the roll. Pour over and spread the ganache along the top of the roll, letting the chocolate drizzle down. Using a sharp serrated knife, carefully cut off the two ends of the roll exposing the beautiful design of the roll inside.
- Using an Ateco 844 closed star tip ⅜” (or any star design tip) pipe out the design on top of the cake like shown on the picture. Description of piping: starting from one edge of the cake roll pipe out one shell in the middle by pushing the cream out and as you pull away release the pressure. Then using the same technique pipe out two shells on each side of the first shell. Continue all along the top of the cake.
- Refrigerate roll until ready to eat. Depending on preference could be served at room temperature or cold from the fridge.