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.