Butterscotch Dip

2 cans (14 ounces each) sweetened condensed milk
2 packages (11 ounces each) butterscotch chips
2 tablespoons vinegar
1 tablespoon ground cinnamon
Apple slices

In a heavy saucepan over low heat, combine milk, chips, vinegar and cinnamon. Cook and stir until smooth. Serve warm with apples. Leftover sauce may be reheated in a heavy saucepan over low heat. Makes about 4 cups.