I make a raspberry buttercream using fresh or frozen raspberries. I just mix them right in after I’ve made the buttercream (but I don’t add any liquids) and I add them to my recipe until it’s the consistency I want. It always works really well, has a great taste and is a fantastic bright pink color. It does have seeds, but none of my customers care because they just love it so much and they know I’m using fresh ingredients (I live in a pretty snobby area though). I’ve never had problems with it getting overly wet or leaky that way.
Leslie Bruckman, Owner of Nom Nom Sweeties