1. Heat oven to 450°F. Prepare CRUMB CRUST.
2. Beat cream cheese, 3/4 cup sugar, sour cream and vanilla in large bowl on medium speed of electric mixer until smooth. Add eggs and flour; beat until blended.
3. Beat cocoa, remaining 1/4 cup sugar and oil with 1-1/2 cups cheese mixture in medium bowl. Place 1-1/3 cups peanut butter chips and milk in small microwave-safe bowl. Microwave at MEDIUM (50%) 30 seconds; stir. If necessary, microwave at MEDIUM an additional 15 seconds at a time, stirring after each heating, until chips are melted when stirred. Gradually add warm peanut butter mixture to remaining vanilla batter; beat on high speed 5 minutes.
4. Spoon peanut butter and chocolate mixtures alternately over prepared crust. Gently swirl with knife or spatula for marbled effect.
5. Bake 10 minutes.* Without opening oven door, decrease temperature to 250°F. and continue to bake 30 minutes. Turn off oven; leave cheesecake in oven 30 minutes without opening door. Remove from oven to wire rack; with knife, loosen cake from side of pan. Cool completely; remove side of pan. Refrigerate until serving time. Cover; refrigerate leftover cheesecake. 12 servings.
1-2/3 cups (10-oz. pkg.) REESE'S Peanut Butter Chips, divided
1-1/4 cups vanilla wafer crumbs (about 40 wafers, crushed)
1/4 cup HERSHEY'S Cocoa
1/4 cup powdered sugar
1/4 cup (1/2 stick) butter or margarine, melted
With knife or food processor, chop 1/3 cup peanut butter chips (reserve remaining chips for cheesecake batter). Stir together crumbs, cocoa, powdered sugar and butter in medium bowl. Stir in chopped peanut butter chips. Press firmly onto bottom of 9-inch springform pan or 9-inch square pan.
* Cheesecakes are less likely to crack if baked in a water bath.