1/2 c. unsalted butter, softened
4 1/2 tbsp. super fine sugar
1 1/3 c. all-purpose flour

TOFFEE TOPPING:

1/2 c. unsalted butter
4 1/2 tbsp. corn syrup
1/2 (14 oz.) can (2/3 c.) sweetened condensed milk (do not use evaporated milk)
1/4 tsp. vanilla extract

CHOCOLATE GLAZE:

7 oz. semi-sweet chocolate

To make Shortbread: Preheat oven to 350 degrees. In small mixer bowl, cream butter and sugar at medium speed of electric mixer until light and fluffy. Stir in flour with wooden spoon. Press into 10 x 6 x 1 1/2 inch baking dish. Bake at 350 degrees for 20 to 25 minutes until golden brown. Cool in pan; set on rack.

To make Toffee Topping: In heavy medium saucepan, combine butter, sugar, corn syrup, and condensed milk. Bring to boiling over medium- high heat, stirring constantly. Boil for 5 minutes, stirring constantly. Stir in vanilla. Quickly pour over cooled shortbread, spreading evenly. Cool on rack at least 1 hour.

To make Chocolate Glaze: In top of double boiler, melt chocolate. Pour over cooled Toffee Topping, spreading evenly. Cool on rack several hours until set. Cut in bars and serve.