Using blueberries is a natural way to get a beautiful color frosting. The blueberries also give a very flavorful and fruity taste to the frosting. To make the frosting- I placed about 1/2 cup of blueberries in a small saucepan on medium heat. I added 1 tablespoon of sugar and 1/2 tablespoon of cornstarch and let it simmer until it thickened. I let it cool while I mixed together 1 cup of softened butter, 1 teaspoon of vanilla and 2 cups of powdered sugar and beat until fluffy. I then put the cooled blueberries in a food processor to make a sauce. I added the sauce to the butter mixture and beat until blended. I had previously made the mini flowers and leaves and kept them frozen for use when needed.