Prepare cake batter according to package directions. Stir in pineapple and walnuts. Pour 2 cups into a greased and floured 9-in. round baking pan and 2 cups into a greased and floured 8-in. round baking pan. Pour remaining batter into a greased and floured 1-1/2-qt. ovenproof bowl.
Bake the layer cakes at 350° for 18-22 minutes or until a toothpick inserted in the center comes out clean. Bake the bowl cake for 35-40 minutes or until a toothpick comes out clean. Cool for 10 minutes before removing from pans to wire racks to cool completely.
In a large bowl, beat cream cheese and butter until fluffy. Gradually add confectioners' sugar alternately with enough milk to achieve desired consistency. Beat in vanilla. Set aside 3/4 cup frosting. Add cocoa to the remaining frosting; beat until smooth.
Place the 9-in. layer on a serving plate; frost with chocolate frosting. Top with 8-in. layer and bowl cake, frosting between layers. Spread remaining chocolate frosting over top and sides of cake.
Divide reserved white frosting in half; tint half orange and half red. Drop by spoonfuls over the top and down the sides of cake.