Walnut-Praline Cake with Cream Cheese Frosting

PREHEAT oven to 350ºF. Grease and flour two 9-inch round baking pans. Process 2/3 cup of the walnuts in food processor or blender until finely ground; set aside. Prepare cake batter as directed on package. Stir in ground walnuts. Pour evenly into prepared pans. Bake 25 min. or until wooden toothpick inserted in centers comes out clean. Cool cake layers in pans 10 min. on wire racks. Remove cakes from pans; cool completely.

MEANWHILE, cover baking sheet with foil; spray with cooking spray. Mix granulated sugar and water in small saucepan. Bring to boil on medium-high heat. Reduce heat to medium-low; simmer 5 min. or until deep golden brown, stirring occasionally. Stir in remaining walnuts; spread onto prepared baking sheet. Cool completely. Carefully remove walnuts from foil; break into small clusters.

BEAT cream cheese and butter in large bowl with electric mixer on medium speed until well blended. Gradually add powdered sugar, beating well after each addition. Remove 2 cups of the frosting; set aside. Melt chocolate as directed on package; cool slightly. Add two-thirds of the chocolate to remaining frosting in bowl; beat until well blended.

CUT each cake layer horizontally into two layers. Stack cake layers on serving plate, spreading chocolate frosting between layers. Frost top and side of cake with reserved plain cream cheese frosting. Gently press walnuts into top of cake. Drizzle with remaining melted chocolate. Store in refrigerator.