Yields 1 1/2 cups sauce.
4 eggs, separated
3/4 cup granulated sugar
1 teaspoon vanilla extract
3/4 cup cake flour
1/4 cup baking cocoa
3/4 teaspoon baking powder
1/4 teaspoon salt
3 cups ice cream, softened
2 (1 ounce) squares unsweetened baking chocolate
1/4 cup butter
2/3 cup evaporated milk, heated to 160 to 170 degrees F
1 cup granulated sugar
In a large mixing bowl, beat egg yolks on high for 3 minutes or until light and fluffy. Gradually add sugar and vanilla, beating until thick and lemon-colored.
Combine flour, cocoa and baking powder; gradually add to egg yolk mixture. Beat on low until well mixed (mixture will be thick).
Beat egg whites and salt until soft peaks form. Fold a small amount into batter until no streaks of white remain; add the remaining egg whites.
Grease a 15 x 10 x 1-inch pan; line with wax paper, then grease and flour paper. Spread batter evenly in pan. Bake at 350 degrees F for 15 minutes or until cake springs back when lightly touched.
Turn out onto a linen towel dusted with confectioners' sugar. Peel off paper and roll up with the towel. Cool for 30 minutes.
Unroll cake; spread with ice cream to within 1 inch of edges. Roll up again (this time without the towel inside cake). Cover with plastic wrap and freeze until serving time.
Chocolate Sauce: In the top of a double boiler over hot water, melt chocolate and butter. Gradually add warm milk and sugar; stir constantly for 5 minutes or until completely dissolved. Spoon over slices of cake.