1/2 cup all-purpose flour
1/4 cup cocoa powder
1 t. baking powder
1/4 t. salt
4 eggs, divided
4 eggs, divided
1/2 t. vanilla
1/3 cup plus 1/2 cup granulated sugar, divided
2 cups whipping cream
1/4 cup powdered sugar
3/4 cup heavy cream
1 cup semi sweet chocolate (either chips or finely chopped pieces)
Grease and line a 15 x 10 jelly roll pan with parchment or waxed paper. Then grease and flour paper. Preheat oven to 375 degrees.
Whisk together flour, cocoa, baking powder, and salt. In a mixer bowl, beat egg yolks and vanilla at high speed for 5 minutes or so until eggs are thick and lemon colored. Gradually add 1/3 cup sugar, beating until sugar dissolves.
In another mixer with clean beaters, beat egg whites at medium speed until soft peaks form. Gradually add 1/2 cup sugar and beat until stiff peaks form. Fold egg yolks into whites very gently. Sprinkle flour mixture over egg mixture and fold gently until incorporated. Spread batter into prepared pan.
Bake at 375 degrees for 12 to 15 minutes. While cake is baking, sprinkle powdered sugar over a clean tea towel. When cake is done, immediately flip cake out of pan and onto towel. Starting at narrow end, roll up cake in tea towel. Cool on a wire rack.
Beat cream to stiff peaks with powdered sugar. When cake is cool, carefully unroll cake and fill with sweetened whipped cream and re-roll (If cake begins to crack, try to re-roll it — the cream will probably hold it together).
Place rolled cake on a serving platter and prepare glaze. Heat 3/4 cup cream to steaming and pour over chocolate in a bowl. Let sit for a minute (leave it alone). Stir until chocolate melts and then let it sit to cool for a few minutes. Pour glaze over cake from the top slowly drizzling, back and forth, so it will slowly drip down over sides. Chill until ready to serve.