Swiss Meringue Buttercream is delicious, versatile, and the BEST frosting to use for layer cakes. Learn how to make it with this Swiss Meringue Buttercream recipe and photo tutorial!This recipe yields 2 lbs 6 oz frosting, or about 10 cups. I find it's usually enough to frost a 9-inch 3-layer cake, but your mileage may vary depending on how much frosting you use between the layers and what kind of decorating you want to do.