1/4 teaspoon salt

1 cup all-purpose flour

For the topping:

1 cup bittersweet chocolate chips

1 cup crushed candy canes

1 cup candied walnuts

1. Preheat the oven to 350 F. Line an 8-inch square baking pan with a piece of foil long enough to press up the sides of the pan, leavine a 1-inch overhang so you can pull the shortbread out in one piece.

2. To make the shortbread: Melt the butter in a medium saucepan on medium heat. Remove from the heat and add the brown sugar and vanilla extract, stirring until smooth. Add the salt and the flour, incorporating them gradually and stirring until thoroughly mixed. Spread the mixture into an even layer on the bottom of the prepared pan. Bake for about 20 minutes, or until the shortbread is golden brown.

3. To add the topping: Remove the shortbread from the oven and sprinkle the chocolate chips over the hot shortbread. Return the shortbread to the oven for 1 to 2 minutes, or just until the chocolate has softened. Remove from the oven and spread the chocolate evenly with a metal spatula. Sprinkle the candied walnuts evenly over the chocolate.

4. Place the pan on a wire rack and cool the shortbread slightly for 20 minutes. Then transfer the pan to the refrigerator to cool for about 40 minutes, or until the chocolate has hardened. Lift the shortbread out of the pans and cut into 16 pieces with a serrated knife. Arrange on a platter and serve.

Make ahead: The cookies may be prepared up to one month ahead and stored in an airtight container in the freezer. Defrost at room temperature for about 15 minutes before serving. They may also be kept up to three days in airtight container at room temperature or in the refrigerator.

(Diane Rossen Worthington is an authority on new American cooking. She is the author of 18 cookbooks, including "Seriously Simple Parties," and a James Beard Award-winning radio show host. You can contact her at www.seriouslysimple.com.)