# HEAT oven to 350°F. Grease and flour 2 (9-inch) round baking pans. Beat cake mix, 1 cup pumpkin, milk, oil, eggs and 1 tsp. spice in large bowl with mixer until well blended. Pour into prepared pans.
# BAKE 28 to 30 min. or until toothpick inserted in centres comes out clean. Cool in pans 10 min. Remove from pans to wire racks; cool completely. Beat cream cheese in small bowl with mixer until creamy. Add sugar, remaining pumpkin and spice; mix well. Gently stir in Cool Whip.
# CUT each cake layer horizontally in half with serrated knife; stack on serving plate, spreading cream cheese filling between layers. (Do not frost top layer.) Drizzle with caramel topping just before serving; sprinkle with nuts. Refrigerate leftovers.