Caramel Frosting
["6 Tbsp. butter", "1/2 c. brown sugar", "1/3 c. milk", "2 c. powdered sugar or enough to thicken"]
["Melt butter; add brown sugar.", "Stir until melted.", "Add milk and boil 2 minutes.", "Let cool.", "Add powdered sugar and vanilla. Stir until smooth."]
["butter", "brown sugar", "milk", "powdered sugar"]