Ingredients
Equipment
Method
Bake the cake
- Heat the oven to 350°F.
- Grease a 10x15-inch jelly roll pan with nonstick cooking spray.
- Line the pan with parchment paper and grease the parchment with nonstick cooking spray.
- Sift the flour, 1/4 cup of the cocoa powder, baking powder, and salt into a medium bowl, then whisk to combine.
- Beat the room-temperature eggs and granulated sugar in a large bowl with an electric mixer on high speed for 5 to 7 minutes, until pale, thick, and ribboning.
- Beat in the vanilla.
- Fold the dry ingredients into the egg mixture in 3 additions until no dry streaks remain.
- Spread the batter evenly in the prepared pan.
- Bake for 10 to 12 minutes, until the cake springs back lightly when touched.
- Dust a clean kitchen towel with the remaining 1 tablespoon cocoa powder.
- Invert the hot cake onto the towel and peel off the parchment.
- Roll the cake up from a short side with the towel inside.
- Cool the rolled cake seam-side down until completely cool, about 1 hour.
Make the filling
- Beat 1 cup of the heavy cream and the confectioners' sugar in a chilled bowl with an electric mixer until medium-firm peaks form.
- Unroll the cooled cake.
- Spread the filling evenly over the cake, leaving a 1/2-inch border.
- Roll the cake back up without the towel and place it seam-side down.
- Refrigerate for 30 minutes.
Make the ganache
- Heat the remaining 1/2 cup heavy cream in a small saucepan until steaming.
- Pour the hot cream over the chocolate chips in a heatproof bowl.
- Let stand for 3 minutes.
- Stir the chocolate and cream until smooth.
- Let the ganache cool at room temperature for 30 to 45 minutes, stirring occasionally, until thick and spreadable.
Assemble and decorate
- Cut a 2-inch diagonal piece from one end of the cake.
- Attach the piece to the side with a little ganache.
- Spread the remaining ganache over the cake, leaving the ends exposed.
- Draw bark lines through the ganache with a fork.
- Refrigerate for at least 30 minutes before slicing.
Notes
For an even roll, roll the cake in the towel while it is still hot and let it cool completely before filling. Store covered in the refrigerator for up to 3 days; it can be frozen. For a dairy-free swap, use dairy-free whipping cream and dairy-free chocolate chips.
