Idaho Potato Cake
["1 c. butter, softened", "2 c. sugar", "2 eggs", "1 c. cold mashed potatoes", "1 tsp. vanilla", "2 c. flour", "1/4 c. cocoa", "1 tsp. baking soda", "1 c. milk"]
["In a mixing bowl, cream butter and sugar until fluffy.", "Add eggs, one at a time, beating well after each addition.", "Blend in potatoes and vanilla.", "Combine flour, cocoa and baking soda; add alternately with milk, blending well after each addition.", "Pour into a greased 13 x 9-inch pan.", "Bake at 350\u00b0 for 40 to 45 minutes.", "Can serve with ice cream, whipped cream or frosting."]
["butter", "sugar", "eggs", "cold mashed potatoes", "vanilla", "flour", "cocoa", "baking soda", "milk"]