Recipe with 3 Tbsp milk yields enough to frost 3 dozen cut-out cookies.
Recipe with 4 Tbsp milk yields enough to frost 4 dozen cut-out cookies.
Add powdered sugar, melted butter and vanilla extra to stand mixer or large bowl.
Mix on High speed, 1-2 minutes.
Add 2 Tbsp on milk and continue to mix on High. Check consistency.
Add 1-2 Tbsp additional milk to achieve desired consistency and mix 1-2 minutes more.
Add food coloring if desired, and mix to combine.
Transfer to pastry bag and pipe onto cookies, or spread with frosting knife as desired.