In the stand mixer, cream the butter until it is lighter in color and fluffier.
Add in the powdered sugar, a third of a cup of powdered freeze dried raspberries, the vanilla extract, and two tablespoons of milk. Use the rubber spatula to mix the ingredients together a bit before covering the stand mixer and mixing on low until creamy.
If the raspberry buttercream is too stiff for what you need to frost, add more whole milk and mix on low.