Melt butter and chocolate in a heavy saucepan over medium-low heat. Stir in sugar, milk, corn syrup, and salt; cook over medium heat, stirring gently, 5 minutes or just until sugar dissolves and sauce is smooth. Remove from heat; stir in vanilla. Cool to room temperature. Pour into gift jars or use for ice cream topping. Cover and chill. Keeps in refrigerator up to 1 month. |