Toffee Bars

Toffee Bars

Toffee Bars Crust: 1 cup (2 sticks) unsalted butter, at room temperature 1 cup firmly packed light brown sugar 1 large egg yolk 1 teaspoon vanilla extract 1/4 teaspoon salt 2 cups all-purpose flour Topping: 7 to 8 ounces milk chocolate, broken into pieces, or 1 1/2...