1. Heat oven to 350°F. Grease and wax paper-line two 8-or 9-inch round baking pans.
2. Place peanut butter chips and shortening in medium microwave-safe bowl. Microwave at MEDIUM (50%) 1-1/2 minutes or until smooth when stirred. Prepare cake mix as directed on package; blend in melted chip mixture. Pour batter into prepared pans.
3. Bake 30 to 35 minutes or until wooden pick inserted in center comes out clean. Cool 10 minutes; remove from pans to wire racks. Cool completely.
4. Frost with PEANUT BUTTER WHIPPED CREAM FROSTING. Refrigerate until serving time. Serve with syrup drizzled over top and sides of cake. Garnish with chocolate curls, if desired. Cover; refrigerate leftover cake. 10 to 12 servings.
PEANUT BUTTER WHIPPED CREAM FROSTING
1-2/3 cups (10-oz. pkg.) REESE'S Peanut Butter Chips
2/3 cup milk
3 cups miniature marshmallows
2 cups (1 pt.) cold whipping cream
1/2 teaspoon vanilla extract
Stir together peanut butter chips, milk and marshmallows in 2-quart saucepan. Heat over low heat, stirring constantly, until chips and marshmallows are melted and mixture is smooth; cool to lukewarm. Beat whipping cream in small bowl with electric mixer until stiff; fold in vanilla and cooled peanut butter chip mixture. About 4 cups frosting.
Variation: Cake may be baked in greased and flour 13x9x2-inch baking pan. Bake 30 to 35 minutes or until wooden pick inserted in center of cake comes out clean. Cool completely in pan on wire rack. Frost with 1/2 recipe PEANUT BUTTER WHIPPED CREAM FROSTING.