Separate eggs. Allow egg whites and egg yolks to stand at room temperature for 30 minutes.
Preheat oven to 375 degrees F. Grease a 15x10x1-inch jelly-roll pan; line with waxed paper. Grease and flour the waxed paper; set pan aside. In a small bowl, stir together flour, cocoa powder, baking powder, and salt; set aside.
In a medium bowl, combine egg yolks and vanilla. Beat with an electric mixer on high speed about 5 minutes or until thick and lemon colored. Gradually add the 1/3 cup granulated sugar, beating on high speed until sugar is almost dissolved.
Thoroughly wash the beaters. In a large bowl, beat egg whites with an electric mixer on medium speed until soft peaks form (tips curl). Gradually add the 1/2 cup granulated sugar, beating until stiff peaks form (tips stand straight). Fold egg yolk mixture into beaten egg whites. Sprinkle flour mixture over egg mixture; fold in gently just until combined. Spread batter evenly in the prepared pan.
Bake for 12 to 15 minutes or until cake springs back when lightly touched. Immediately loosen edges of cake from pan and turn cake out onto a kitchen towel sprinkled with powdered sugar. Remove the waxed paper. Roll up towel and cake into a spiral, starting from one of the cakes short sides. Cool on a wire rack.
Unroll cake and remove towel. If desired, stir raspberry liqueur into raspberry preserves. In a chilled large bowl, stir ice cream with a wooden spoon just until softened enough to spread. Spread ice cream on cake to within 1 inch of the edges. Spread raspberry preserves on ice cream to within 1 inch of edges. Roll up cake; wrap in foil. Freeze for 6 hours.
Spread Rich Chocolate Frosting over cake roll. Using the tines of a fork, score the frosting lengthwise so it resembles tree bark. Cover and freeze for at least 2 hours or up to 1 week.
Let stand at room temperature for 10 minutes before serving. If desired, shape marzipan into holly leaves and holly berries; roll berries in red decorative sugar. Garnish log with marzipan berries and leaves. Makes 10 servings.
Rich Chocolate Frosting
In a heavy, small saucepan, combine unsweetened chocolate and butter. Heat and stir over low heat until chocolate melts. Remove from heat. Add 1-1/2 cups sifted powdered sugar and 1/4 cup milk, stirring until smooth. Add 1-1/2 cups sifted powdered sugar; stir in enough additional milk (1 to 2 tablespoons) to make of spreading consistency. Spread immediately over cake roll.