Great Grandma M. Vereen Morris John's Rocky Road Cake

1/2 c. Margarine
1/2 c. Oil
1 c. Water
In a small saucepan bring to boil. Remove from heat and let cool 10 min.
2c. Flour
1 3/4 c. Sugar
1 tsp. Salt
1/4 c. Cocoa
Combine in large bowl in large bowl, pressing out lumps. Pour in liquid mixture and stir till smooth.
2 eggs
1/2 c. Buttermilk
1 1/2 c. Vanilla
1 tsp. Baking soda
Beat in eggs. Add remaining ingredients until fully mixed.
Pour into greased 9x13 pan.
Frosting:
1/4 c. Cocoa
1/3 c. Buttermilk
1/2 c. Margarine
Combine ingredients in a saucepan.  Heat mixture over low heat until margarine melts and mixture is smooth.
Transfer mixture to a bowl. Beat 3 1/2 c. Powdered sugar until mixture is satiny and spreading consistency.
2/3 c. Mini marshmallows
1/2 c. Chopped walnuts
1 tsp. Vanilla
Stir in ingredients and spread on top of cake.