1/4cupegg whitesabout 2 egg whites from large eggs
Confectioners’ sugar for dusting
Chocolate glaze and topping
4oz.chocolatefinely chopped
1/2cup/120 g heavy cream
Assorted chocolate bonbons
Instructions
Buttercream filling
In a saucepan, bring the cream to a simmer. Remove from the heat and pour in the chopped chocolate. Whisk to combine. Transfer the mixture to a shallow dish and transfer to the refrigerator. Stir the mixture intermittently to speed cooling.
In a large bowl beat the butter until creamy. Add the confectioners’ sugar and beat until light and fluffy, about 4 minutes. Beat in the vanilla extract and pinch of salt.
Remove half of the frosting and place it in a piping bag fitted with a 1/2-inch decorator tip (or no tip, and a 1/2-inch hole cut in the end). Beat the cooled chocolate mixture and 2 tablespoons dark cocoa into the remaining frosting. Transfer the chocolate frosting to a piping bag fitted with 1/2-inch decorator tip (or no tip, and a 1/2-inch hole cut as previously mentioned). Set aside. Keep the bags at room temperature.
Sponge roll
Gently fold in the cake flour using a large rubber spatula. Set aside.
Beat the egg whites in a separate bowl until soft peaks form. Gently fold the beaten egg whites into the yolk mixture.
Preheat the oven to 350°F. Grease a 10x 15-inch baking sheet with vegetables shortening and line it with parchment paper (the greased surface helps the paper to stick to the pan). Carefully spread the mixture in an even layer over the parchment with an offset spatula.
Bake for 8 to 10 minutes, or until the cake just starts to brown around the edges. The cake may look glossy and underdone in the middle, but looks can be deceiving. Check the cake’s center by pressing your finger on the cake. If it springs back, it’s done. Be careful not to over-bake this cake, or it break into pieces as you try to roll it.
Let the cake cool slightly. Run a knife around the edge of the pan and turn the cake onto a work surface dusted with powdered sugar (put a piece of waxed paper down first and clean-up will be a snap). Peel off the parchment paper. Trim the brown edges away from the cake. Let the cake cool completely.
Pipe spaced lines of chocolate frosting across the length of the cake. Leave just enough space to allow for same-sized lines of white icing between the chocolate icing. Pipe the white frosting between the chocolate rows, filling the gaps completely. You should have leftover chocolate frosting, reserve it for later use. Gently begin to roll the cake, starting at a long side, pushing it forward with your fingers. Roll the cake up completely and wipe away any excess frosting that gets squished out during rolling. Place the cake roll on a large sheet of waxed paper (or parchment) and roll the cake up into the paper. Chill the cake in the freezer until firm.
Chocolate glaze and topping
Place heavy cream in a large microwaveable bowl. Heat in the microwave at 40 second intervals until very hot but not boiling (you can do this on the stove top if you don’t have a microwave). Stir in chopped chocolate. Let stand for 3 minutes then begin gently stirring mixture. You can use a whisk, but do not whisk vigorously as it will create air bubbles in the finished glaze.
Remove cake from freezer and place it on a grid baking rack; place the rack on top of a large baking pan. Pour glaze over entire surface, allowing the excess to drip into the pan. Let stand for 2 minutes, and then transfer the cake to the freezer.
Transfer the remaining chocolate frosting to a piping bag fitted with a large open star tip. Pipe an undulating line of frosting on top of the cake. Garnish with chocolate bonbons. Cut the cake into pieces with a warmed knife, cleaning between slices, while it is still cold. Let the slices come to room temperature before serving.
Notes
Recipe source: Professional Baking by Wayne Gisslen (6th edition) with my adaptations and notes.
Keyword chocolate buttercream, vanilla buttercream, white chocolate ganache