Mix all together and pour into 3 greased and floured cake pans (2 if necessary). Bake at 325 degrees for 35 minutes or until cake springs back. Set out to cool.
For icing, melt margarine and milk together in microwave. Mix sugar and cream cheese by adding milk and margarine mixture by spoonfuls until icing is creamy and spreadable. Spread on cake layers and outside of cake.