1. Prepare PUMPKIN FILLING. Heat oven to 375°F. Line 15-1/2 x10-1/2 x 1-inch jelly-roll pan with foil. Generously grease foil.
2. Beat egg whites in large bowl on high speed of mixer until soft peaks form; gradually add 1/2 cup sugar, beating until stiff peaks form. Set aside. Beat egg yolks and vanilla in medium bowl 3 minutes; gradually add remaining 1/4 cup sugar, beating 2 additional minutes.
3. Combine dry ingredients; add to yolk mixture alternately with water, beating on low speed just until smooth. Gradually fold chocolate mixture into beaten whites with rubber spatula until well blended. Spread batter evenly in prepared pan.
4. Bake 12 to 15 minutes or until top springs back when touched lightly. Immediately loosen cake from edges of pan; invert on clean towel sprinkled with powdered sugar. Carefully peel off foil. Immediately roll cake in towel, starting from narrow end; place on wire rack to cool completely. Carefully unroll cake; remove towel. Spread cake with filling; reroll without towel.
5. Spoon glaze over top . Refrigerate until just before serving. Cover; refrigerate leftover dessert. Makes 18 servings.
PUMPKIN FILLING: Beat 1 package (3 oz.) softened cream cheese with 1/2 cup powdered sugar. Beat in 1/2 cup cooked pumpkin, 1/2 teaspoon ground cinnamon, 1/8 teaspoon ground nutmeg and 1/4 teaspoon vanilla extract. Slowly add 1/2 cup whipping cream, beating until slightly thickened. Refrigerate about 2 hours.
CHOCOLATE GLAZE: Melt 2 tablespoons butter in small saucepan over low heat; add 2 tablespoons HERSHEY'S Cocoa and 2 tablespoons water, stirring until smooth and slightly thickened. Do not boil. Remove from heatl cool slightly. Gradually add 3/4 cup powdered sugar and 1/2 teaspoon vanilla extract, beating with whisk until smooth. About 1/2 cup.