Preheat oven to 350 degrees F. Prepare cake mix according to package directions and bake in in preheated oven in an 8x11/2-inch round baking pan. Remove cake from pan and cool as directed on package. Invert cake onto serving plate.
In a small bowl, stir together white frosting and peanut butter. Use the mixture to frost the top center of the cake in the shape of a monkey face. Place 1 to 2 tablespoons of the chocolate frosting in a plastic bag; set aside. Frost the rest of the cake with remaining chocolate frosting and pat the cereal into the chocolate frosting only. Snip one corner off the plastic bag and pipe a nose and a mouth onto face. Place two chocolate kisses upside down onto the face for eyes.
Cut sugar cookie in half and place the halves on each side of the cake for ears. Before serving, peel a banana and brush the peel with lemon juice to prevent browning. Place the peel on plate above the monkey head. Makes 8 servings.