Sift dry ingredients together and add to mixture. Add remaining ingredients and hand-mix well. Pour into a greased 9-x-13-inch pan and bake at 350ยบ for 30 minutes. Spread marshmallow creme or melted marshmallows over cake. Allow cake to cool completely before frosting.
For frosting, melt butter over low heat until soft; add remaining ingredients and mix well. Spread on cake.