Sir together first 5 ingredients.
Stir mayonnaise into above mixture.
Then stir in water and vanilla.
Pour into greased and floured 9x13 pan or 2 round cake pans.
Bake at 350 degrees about 30 minutes or until toothpick comes out clean from center of cake and/or cake has pulled away from side of pans.
Frost with Buttercream frosting.