Combine first 3 ingredients; stir well. Press mixture firmly on bottom of a lightly greased 9" springform pan. Bake at 325° for 14 minutes; let cool.
Beat cream cheese at medium-high speed with an electric mixer until creamy. Gradually add sweetened condensed milk, beating just until blended. Add 1/3 cup whipping cream and next 3 ingredients, beating just until blended. Add eggs, 1 at a time, beating just until yellow disappears. Stir in chocolate chunks and crushed candies.
Pour batter into baked crust. Bake at 325° for 52 to 55 minutes or until edges are set and center is almost set. Turn off oven. Immediately run a knife around edge of pan, releasing sides. With oven door slightly open, let cheesecake stand in oven 1 hour. Remove from oven; cool completely on a wire rack. Cover and chill 8 hours. Remove sides and bottom of pan; place cheesecake on a serving plate.
Pour 3/4 cup whipping cream into a microwave-safe bowl. Microwave at HIGH 1 minute or until hot. Add 1 1/2 cups semisweet morsels; stir until chocolate melts and mixture is smooth. Pour ganache over chilled cheesecake, allowing ganache to spill over edges of cheesecake; smooth ganache with an offset spatula. Let stand 10 minutes before garnishing. Store in refrigerator.
For easy cleanup, place wax paper strips under edges of cheesecake on serving plate. When you pour the ganache, it will drip onto the wax paper. Gently remove wax paper strips after the 10-minute standing time.