2 sticks butter (room temperature) (I always use salted.)
3 - 4 cups powdered sugar
2 tablespoons seedless raspberry preserves
1 - 2 tablespoons water or milk (or any other liquid)
Beat the butter on high speed for about 3 - 5 minutes until light and fluffy. Turn mixer to low-medium speed and add powdered sugar one cup at a time. Add raspberry preserves and water, until desired consistency is reached. Beat well for about 3 more minutes.