Mennonite Caramel Frosting

3 cups packed brown sugar
1 cup top milk or thin cream
2 tablespoons butter
1 teaspoon vanilla extract

Mix ingredients together in a saucepan. Stir until sugar is dissolved; cook syrup until it forms a soft ball when dropped in cold water (238 degrees F). Cool until you can hold your hand on the bottom of the pan. Beat until creamy and spread on cake.