Someone probably thought of this before me, but no one has posted it before me:)
I was craving some Once't in a Blue Moon Bakery raspberry brownies and looking up recipes online for raspberry buttercream, when it dawned on me to just use Mom's old frosting recipe and throw in some frozen raspberries. It turned out delicious and a very delicate shade of pink, very pretty, indeed.
Some butter, softened
Some powdered sugar, ok, lots
Add milk and beat with beaters until it is the consistancy you like
Throw in frozen (thawed) raspberries
I didn't measure; sorry.