1. Prepare CHOCOLATE CRUMB CRUST. Heat oven to 425°F.
2. Beat cream cheese, 3/4 cup sugar and 1 teaspoon vanilla in large bowl until smooth. Add eggs; beat until well blended. Stir together cocoa and remaining 1/4 cup sugar in medium bowl. Add oil, remaining 1/2 teaspoon vanilla and 1-1/2 cups cream cheese mixture; blend well. Stir jam to soften. Add jam, flour and food color, if desired, to remaining mixture in bowl; blend well.
3. Pour half of raspberry mixture into prepared crust. Drop small spoonfuls of about half of chocolate mixture over raspberry. Repeat procedure with remaining mixture, ending with chocolate on top; gently swirl with knife or metal spatula for marbled effect.
4. Bake 10 minutes. Reduce oven temperature to 250°F; continue baking 55 minutes or until center appears set. Remove from oven to wire rack. With knife, loosen cake from side of pan. Cool completely; remove side of pan. Cover; refrigerate several hours before serving. Serve with RASPBERRY SAUCE and raspberries, if desired. Cover; refrigerate leftover cheesecake. 10 to 12 servings.
CHOCOLATE CRUMB CRUST: Heat oven to 350°F. Stir together 1-1/4 cups vanilla wafer crumbs (about 40 wafers, crushed), 1/4 cup powdered sugar and 1/4 cup HERSHEY'S Cocoa in medium bowl. Stir in 1/4 cup (1/2 stick) melted butter or margarine. Press mixture onto bottom and 1/2 inch up side of 9-inch springform pan. Bake 8 to 10 minutes; cool slightly.
RASPBERRY SAUCE: Stir together 1/4 cup sugar and 2 teaspoons cornstarch in small saucepan; stir in 1 package (10 oz.) frozen red raspberries, thawed. Cook over medium heat, stirring constantly, until mixture boils; boil and stir 1 minute. Cool; press through sieve to remove seeds. About 1 cup sauce.