Ingredients:
- 1 cup egg whites, room temperature
- 1 cup superfine granulated sugar
- 0.75 cup cake flour
- 0.25 cup Dutch-processed cocoa powder
- 1 tsp cream of tartar
- 0.25 tsp salt
- 1 tsp pure vanilla extract
- 2 cups heavy whipping cream, chilled
- 0.5 cup powdered sugar
- 1 tsp espresso powder
- 1 cup semi-sweet chocolate chips
- 0.5 cup heavy cream (for ganache)
- 1 tbsp light corn syrup
Instructions:
- Preheat oven to 350°F (175°C). Line a 10x15 inch jelly roll pan with parchment paper.
- Sift cake flour and cocoa powder together three times to ensure maximum aeration and prevent clumping.
- In a stand mixer, whip egg whites with salt and cream of tartar until soft peaks form. Gradually add superfine sugar while whipping on medium-high until stiff, glossy peaks form.
- Gently fold the dry ingredients and vanilla extract into the meringue until just combined, being careful not to deflate the whites.
- Spread the batter evenly into the prepared pan and bake for 12-15 minutes or until the top springs back when touched.
- Immediately invert the hot cake onto a lint-free kitchen towel dusted with powdered sugar. Roll the cake and towel together from the short end and let cool completely.
- Whip 2 cups heavy cream with powdered sugar and espresso powder until stiff peaks form. Unroll the cooled cake, spread the filling, and re-roll.
- Prepare ganache by melting chocolate chips with 0.5 cup heavy cream and corn syrup. Spread over the log and chill until set.