For OREO Crumb Crust: Combine OREO Base Cake and butter. Press evenly onto bottom of parchment paper-lined 9-1/2 inch springform pan. Bake 10 minutes in 325°F standard oven. Remove from oven and cool completely on wire rack.
For Cheesecake: Mix cream cheese in bowl of mixer fitted with paddle attachment on low speed until smooth, scraping side of bowl as needed. Gradually blend in sugar, mixing well after each addition.
Mix eggs and egg yolk in medium bowl. Gradually add to cream cheese mixture, mixing after each addition. Stir in cream and vanilla until blended. Fold in OREO Pieces.
Pour batter over cooled crust. Bake in a water bath in 325°F oven 60 to 65 minutes or until center is set. Remove from water bath and cool completely in pan on wire rack. Refrigerate several hours or overnight.
For Whipped Cream: Whip cream to soft peaks. Divide among 6 bowls. Blend in 1 oz. food coloring to each bowl to create 6 colors. Place each colored cream in separate pastry bag fitted with #5 plain round tip. Pipe round mounds of red whipped cream around outer edge on top of cheesecake. Follow with orange, then yellow, green, blue and violet, piping mounds adjacent to the previous color. Refrigerate. Cut into 12 pieces. Keep refrigerated until ready to serve.