BUTTERSCOTCH SAUCE

1 1/2 cups packed brown sugar
1/2 cup light corn syrup
4 tablespoons (1/4 cup) butter
1/2 cup heavy (whipping) cream
1 teaspoon vanilla extract

In a medium pot, heat the sugar, syrup and butter over medium-low heat to boiling, stirring constantly.

Remove from heat; stir in the cream and vanilla. Stir just before serving.

Source: Betty Crocker's Cookbook, 1972 edition