This recipe makes enough to (generously!) frost two dozen cupcakes.
½ cup (100 grams) butter
3 cups powdered sugar
½ tsp vanilla
2 to 3 Tbsp milk
Cut butter into pre-measured powdered sugar. Add vanilla. Beat on medium speed until mixture is crumbly. Add milk – one tablespoonful at a time – beating constantly until reaching spreading consistency. Spread onto (cooled) cupcakes.