Place butter in the mixer bowl and whip on medium-high speed until light & fluffy, 2-4 minutes. Add the vanilla and pinch of salt and whip up well. Gradually add powdered sugar, mixing on low.
Pour 4 tablespoons (with mixer running) of milk or cream and whip well; depending on desired consistency (less milk for piping) a little extra for spreading typically. Add more milk as needed, whip for 4-8 minutes until cloud-like light!
If you'd like to tint the frosting, add tiny amounts of gel food coloring until desired tint is achieved. If adding an extract, add at end and whip for additional minute. Spread or pipe onto baked goods. Add sprinkles, if desired
BACKING HACK | If piping, place tip in bottom of decorating bag, place bag/tip in tall heavy glass, fold over edges of bag and scoop in frosting.