Buttermilk Spice Cake and Buttercream Frosting

2 cups sugar
1 cup butter or margarine -- soften
4 eggs -- beaten
3 cups all-purpose flour
1 teaspoon baking powder
1 teaspoon baking soda
1 teaspoon ground cinnamon
1 teaspoon ground cloves
1 teaspoon ground nutmeg
1 cup buttermilk

BUTTER CREAM FROSTING
1/2 cup shortening
1/2 cup butter or margarine -- soften
1 teaspoon vanilla extract
4 cups confectioners' sugar
3 tablespoons milk

For the cake, in a mixing bowl, cream sugar and butter. Add eggs; beat well. Combine dry ingredients; add to creamed mixture alternately with buttermilk. Mix well. Pour into a greased and floured 13x9x2" baking pan. Bake at 350 degrees for 35-40 minutes or until the cake tests done. Cool. For frosting, cream shortening and butter in a mixing bowl. Add vanilla. Gradually beat in sugar. Add milk; beat until light and fluffy. Frost cake.