Old-Fashioned Caramel Icing

3 cups granulated sugar
3/4 cup milk
1 cup granulated sugar
3 tablespoons butter or margarine
1 teaspoon vanilla extract

Boil 3 cups sugar and milk for 3 minutes. In a skillet melt 1 cup sugar over medium heat, stirring. Add sugar and milk mixture, stirring quickly. Add margarine and vanilla extract. Stir vigorously until of spreading consistency. If mixture seems too thick, add a little milk.