Mississippi Mud cake

I found this recipe on southern plate. By the looks of it, It reminds me of a mix of my of grandma Maisak's chocolate sheet cake (my #1 favorite), and my favorite ice cream rocky road! I have to give this one a try!

cake
2 cups plain flour
2 cups sugar
1/2 t. salt
1 t. baking soda
1 stick margarine
1/2 cup oil
4 T. cocoa
1 cup plus 1 t. cold water, divided
2 eggs, beaten
1/2 cup buttermilk
1 10oz. bag mini marshmallows

Sift flour, sugar, salt, and soda together. Bring margarine, oil, cocoa, and one cup water to a boil. Add to flour mixture. Add eggs, one teaspoon cold water, and buttermilk. Mix well. Pour into a greased and floured 9X13 pan and bake at 375 for 25to 30 minutes. Top with marshmallows while warm. Pour icing over top.

Icing

1 stick margarine
3 T. cocoa
6 T. milk
1 16 oz. box confectioner’s sugar
1 t. vanilla
Combine margarine, cocoa, and milk. Bring to a boil. Add sugar and mix well. Add vanilla. Pour over hot cake as soon as it come out of oven. Note: Chopped nuts are great added to cake.