Combine first 3 ingredients; press mix evenly onto bottom and 1-1/2" up sides of 9" springform pan. Sprinkle chopped nougat bars evenly over bottom; set aside. Beat cream cheese at high speed w/ mixer til light and fluffy; gradually add 1/2C sugar, mixing well. Add eggs, one at a time, beating after each addition. Stir in chocolate chips and vanilla; beat til blended. Spoon over candy layer. Bake at 350? for 30min. Remove from oven and run knife around edges of pan to release sides. Let cool to room temperature on wire rack. Cover and chill at least 8 hrs. To serve, remove cheesecake from pan; pipe or dollop whipped cream on top. Yield: one 9" cheesecake.