Caramel Sauce

In a heavy 2 quart saucepan combine 1/2 cup whipping cream, 1/2 cup butter, 3/4 cup packed dark brown sugar, and 2 tablespoons light corn syrup.  Bring to boiling over medium high heat (about 5 -6 minutes), whisking occasionally.  Reduce heat to medium.  Boil gently for 3 minutes more.  Remove from heat.  Stir in 1 teaspoon vanilla.  Let sauce cool for 15 minutes