1 / 2 cup butter , softened 1 / 2 cup shortening 1 cup sugar 1 teaspoon vanilla Directions :
1 . Preheat oven to 325 ° F . 2 . In a large mixing bowl , sift together dry ingredients . Add oil , coffee and milk and mix at medium speed for 2 minutes . Add eggs and vanilla and beat 2 more minutes . Expect batter to be thin . 3 . Pour into a 9 " x 13 " greased and floured pan or 2- 9 " round pans . Bake 9 x 13 pan for about 45 minutes or 9 " pans for about 30 minutes . Cool in pans for about 15 minutes and then cool completely on racks . 4 . While cake is cooling make the icing : Combine the milk and flour in a saucepan and cook over low heat until thick , whisking constantly . Cover and refrigerate until chilled . 5 . In a medium bowl , beat butter , shortening , sugar and vanilla until creamy . Add chilled milk and flour mixture and beat for 10 minutes . Frost cooled cake and enjoy ! The frosting sounds intimidating , but it is worth it ! By the way , for some reason , we prefer this cake chilled , right out of the refrigerator . The rich chocolate and cool frosting just seem to taste best this way .