In 2-quart heavy saucepan, heat granulated sugar over medium-low heat 6 to 8 minutes, stirring constantly with wooden spoon and watching carefully, until sugar begins to melt. As sugar begins to melt, stir with wooden spoon until sugar is melted and golden brown. (Sugar becomes very hot and could melt a plastic spoon.) Remove from heat; carefully stir in butter and 1 tablespoon of the milk (mixture will become lumpy). Return to medium-low heat, stirring constantly, until mixture is smooth. Cool 5 minutes.