- 6 egg whites
- 6 egg yolks
- ¾ cup sugar
- ⅓ cup unsweetened cocoa
- 2 tsp vanilla 
- dash salt
- keep at room temperature for at least 1 hour
- 1½ cup heavy cream, chilled
- ½ cup confectioner's sugar
- ¼ cup unsweetened cocoa
- 2 tsp instant coffee
- 1 tsp vanilla 
- Grease the bottom of a 15½x10½x1" jelly-roll pan; line with waxed paper, grease lightly.
- Preheat oven to 375 °F.
- In a large bowl of an electric mixer beat egg whites at high speed until soft peaks form when beaters are slowly raised.
- Add ¼ cup sugar, 2 tsp at a time, beating until stiff peaks form when beater is slowly raised.
- With same beaters beat yolks at high speed, adding the remaining ½ cup of sugar 2 tsp at a time, until mixture is very thick-about 4 minutes.
- At low speed beat in cocoa, vanilla and salt just until smooth.
- With wire whisk or rubber scraper using and under and over motion, gently fold the cocoa mixture into the beaten egg whites, just until they are blended(no egg white should show).
- Spread evenly in the pan, bake 15 minutes, just until the surface springs back when gently pressed with fingertip.
- Sift confectioner's sugar in a 15x10" rectangle, on a clean linen towel.
- Turn cake out onto sugar, lift off pan, peel paper off of cake.
- Roll up cake jelly-roll fashion, towel and all, starting at the short end.
- Cool completely on rack, seam side down- at least 30 minutes.
- To make the filling: combine filling ingredients in medium bowl.
- Beat using an electric mixer until thick and then refrigerate.
- Unroll cake, spread with filling to 1" from the edge, re-roll / refrigerate 1 hour before serving.
- To serve sprinkle with confectioner's sugar.
- You may make this cake a week ahead, then freeze it wrapped in foil.
- Let stand at room temperature for 1 hour before serving.