Thanks to Theo's Mom for posting this recipe for "puddle cake" waaaaay back in November of last year. (I have it hanging on my fridge.
Yu can even make it with toddlers, and because it's egg-free you can lick the beater! (fork)
1-1/2 c. flour
1 c. sugar
1 tsp. baking soda
1/2 tsp. salt
5 T. cocoa
6 T. oil
1 T. vinegar
1 tsp. vanilla
1 c. water
Put all dry ingredients into an 8x8 baking pan. Sift together with fork. Have child dig 3 holes (puddles): one large, one medium, one small. Put the vanilla into the small hole, the vinegar into the medium hole, and the oil into the large hole. Pour the water over the top and mix well with the fork. Bake at 350 for 30 minutes or til toothpick comes out clean. Frost as desired or sprinkle w/powdered sugar.
From posts that were after it, apparently Pillsbury chocolate frosting is dairy-free, as is Duncan Hunes, if I remember correctly.
HTH!