Chocolate Mayonnaise Cake

Chocolate Mayonnaise Cake (with Brown Sugar Frosting)
1 c water
1 c mayonnaise
1 t vanilla
2 c flour
1 c sugar
3 T cocoa
2 t baking soda
Brown Sugar Frosting:
1/2 c packed brown sugar
1/4 butter, cubed
2 T milk
1 3/4 c powdered sugar

1. Preheat oven to 350* and grease a 9x9 pan.
2. In a large bowl, combine water, mayonnaise, and vanilla.
3. In a separate bowl, combine flour, sugar, cocoa, and baking soda; stir into mayonnaise mixture.
4. Pour into pan and bake for 35 minutes, until passes toothpick test. Cool completely.
5. For frosting: In a small pan, combine brown sugar and butter and heat until bubbly; remove from heat, add milk, and then stir in powdered sugar.