SPRAY 9-inch tart pan with removable bottom with nonstick cooking spray.
MICROWAVE 1 cup milk chocolate morsels in uncovered, small microwave-safe bowl on MEDIUM-HIGH (70%) power for 1 minute; STIR. The morsels may retain some of their original shape. If necessary, microwave at additional 10- to 15-second intervals, stirring until melted.
STIR crumbs and butter in medium bowl. Stir in melted chocolate until moistened. Press mixture onto bottom and up sides of tart pan using dampened fingers. Refrigerate.
COMBINE cream and corn syrup in medium, heavy-duty saucepan. Bring to a boil over medium heat. Remove from heat; stir in semi-sweet morsels. Let stand for 5 minutes. Stir until chocolate is melted. Spread over prepared crust. Refrigerate for 30 minutes.
MICROWAVE caramel topping in medium, microwave-safe bowl on HIGH (100%) power for 1 to 1 1/2 minutes or until heated through, stirring halfway through cooking time. Add remaining milk chocolate morsels; stir until chocolate is melted.
SPRINKLE 2/3 cup nuts over chilled tart. Carefully drizzle milk chocolate caramel mixture over nuts. Sprinkle with remaining nuts. Cover tart loosely. Refrigerate for at least 3 hours or overnight. Remove side of tart pan and place on serving platter.