I have a wedding cake to make the beginning of September and I'm looking for a good buttercream recipe. My homemade buttercream seems to droop, never holds its shape. The bride is wanting the bottom tier to be a rosette cake. What's the best icing recipe for this? 

Thanks !' 

Here is a link to the buttercream I use, it does gave shortening in it but you would never know and I find it necessary to get a good crust on the BC :) 

http://www.onecheaputahchick.com/fluffy-buttercream-recipe/