Hi -- I just made the chocolate malt buttercream from Dorie Greenspan's Baking From My Home to Yours cookbook. The taste is fabulous, but the texture is a bit grainy. I followed the recipe to the letter. I creamed the butter and brown sugar well, and I sifted the powdered sugar and added it very gradually. Is there any way to remedy the grainy texture at this point? It's certainly not inedible and I plan to use it as is if I can't fix it, but I'm puzzled about the texture.