Favorite Caramel Frosting
["3 c. sugar, divided", "3/4 c. milk", "1 egg, beaten", "pinch of salt", "1/2 c. butter, cut up"]
["Sprinkle 1/2 cup sugar in a heavy saucepan; place over medium heat.", "Cook, stirring constantly, until sugar melts and syrup is light golden brown.", "Combine remaining 2 1/2 cups sugar, milk, beaten egg and salt, stirring well; stir in butter.", "Stir butter mixture into hot caramelized sugar.", "(The mixture will tend to lump, becoming smooth with further cooking.)", "Cook over medium heat, stirring frequently, until a candy thermometer registers 230\u00b0 (about 15 to 20 minutes).", "Cool 5 minutes.", "Beat with a wooden spoon to almost spreading consistency (about 5 minutes) and spread on cooled cake.", "Yield:", "about 2 1/2 cups."]
["sugar", "milk", "egg", "salt", "butter"]