This is a very old recipe from my Aunt Martha in 1981.She always made this whenever my family would visit..so I know it is older than this date as she has been making this for a long time ..This jelly roll cake is so rich and chocolaty you will want to have a second piece to make sure you got a good taste of the filling too. Don't be intimidated by the wordy recipe- just making sure you can follow along. This is not hard to make.
If you don't want to make the cake part from scratch; try my "angel food jelly roll" recipe- just add the cocoa and grated chocolate to the batter.
Separate egg yolks into small bowl and whites into large bowl of electric mixer.
Preheat oven to 375^ Lightly grease bottom of a 15x10 x1 inch jelly roll pan; then line with waxed paper; on the bottom only not on the sides.
2Beat egg whites at hight speed just until soft peaks form. Gradually beat in 1/4 cup of the sugar, beating until stiff peaks form. It should look shiny and moist.
With the same beater at high speed, beat egg yolks with rest of the sugar until thick lemon colored about 5 minutes.
3Turn to low speed and beat in cocoa and extracts just until combined. Add flour and baking powder. Gently fold yolk mixture into egg whites just until combined. Turn batter into prepared pan, spread out evenly. Bake for about 12 to 14 minutes, or just until surface springs back when gently pressed with finger.
4On a clean towel(not terry cloth), sift powdered sugar onto towel. Turn out cake onto sugar, gently peel off waxed paper. With a sharp knife, trim edges. So cake rolls smoothly.Starting with long edge, roll up cake in towel, jelly-roll fashion.( Cake tends to crack slightly when rolled). Place seam side down on wire rack 30 minutes, or until cooled.
In a medium bowl, combine cream and sugar. Refrigerate,covered ,1 hour, or until well chilled.
While that is chilling, sprinkle gelatin over water in small bowl or measuring cup. Let stand 5 minutes to bloom(soften).Place over hot water; stir to dissolve. Cool for 30 minutes. The mixture should be liquid. Stir in the rum.
6Remove cream mixture from refrigerator and Using portable electric mixer, at high speed, beat cream mixture until stiff. At medium speed now gradually add gelatin mixture; continue beating until well combined. Return to refrigerator until firm about 30 minutes.
Beat at high speed, until smooth and of spreading consistency.
7ASSEMBLY OF ROLL:
Gently unroll cake and towel; remove the towel. Spread cake with 3/4 of the filling; reroll. Place, seam side down on serving tray. Spread top and sides with remaining filling. Chill for 1 hour,or until ready to serve.
Just before serving garnish with chocolate curls.