PREHEAT oven to 325° F. Wrap outside bottom and side of 9-inch springform pan with double layer of heavy-duty foil.
COMBINE graham cracker crumbs, butter, granulated sugar and nuts in medium bowl. Press crumb mixture onto bottom and 1-inch up side of prepared pan.
REMOVE 2 tablespoons of morsels and set aside for garnish. Heat milk and remaining morsels in medium saucepan over low heat until morsels are melted and mixture is smooth; remove from heat. Cool to room temperature.
BEAT cream cheese, granulated sugar, flour and vanilla extract in large mixer bowl until combined. Add butterscotch mixture; beat until smooth. Add eggs, beat just until combined. Pour into prepared pan. Place pan in large roasting pan; fill roasting pan with warm water half way up side of springform pan.
BAKE for 1 1/4 to 1 1/2 hours or until 2 1/2-inch area around outside edge appears set when gently shaken. Carefully remove cheesecake from water. Pull foil away from pan and lift springform pan out of foil to wire rack. Cool on wire rack for 15 minutes. Run knife around edge of cheesecake. Cover; refrigerate for 6 hours or overnight.
TO SERVE: Remove side of pan. Spread caramel topping over top of cheesecake. Pipe outer edge of cheesecake with whipped topping. Garnish with reserved morsels, if desired.