2 c shortening
2 sticks butter
2 tsp vanilla
2 lbs powdered sugar, sifted
Beat the shortening and butter together until light, fluffy, and doubled in volume. Add the vanilla, and slowly add the powdered sugar on the lowest speed until smooth and creamy. 🙂
The above is the way Grandma and Aunt Anne make their buttercream for wedding cakes. I like to use 2 c butter (4 sticks) + 2 c shortening, because I like more butter flavor in my buttercream. And I add an extra 2 tsp of vanilla. 🙂