In saucepan, combine butter, shortening ... buttermilk to which soda has been added. Bake at 350 degrees for 30 minutes. Frost with Cool Whip Frosting.
Combine brown sugar, butter and ... thick and syrupy. Cool until cold. Fold into large Cool Whip right before you want to serve it. Frost cake. Refrigerate cake what is ... spice or pumpkin cake.