Ingredients

Makes about forty 3- by 1-inch bars

　　For shortbread layer

　　2 cups all-purpose flour

　　2 sticks (1 cup) cold unsalted butter, cut into bits

　　2/3 cup confectioners' sugar

　　1/2 teaspoon salt

　　

For topping

1/2 stick (1/4 cup) unsalted butter

　　1/2 cup firmly packed brown sugar

　　3/4 cup canned coconut cream such as Coco Lopez

　　1/4 cup heavy cream

　　2 tablespoons fresh lemon juice

　　a 7-ounce package sweetened flaked coconut

　　a 7-ounce jar macadamia nuts (about 11/3 cups), large pieces halved

　　

Step 1

Preheat oven to 350° F. and butter a 13- by 9-inch baking pan.

　　

Make shortbread layer:

Step 2

In a food processor pulse shortbread ingredients until mixture just forms a dough. Pat dough evenly onto bottom of pan and bake 20 minutes, or until pale golden.

　　

Make topping while shortbread is baking:

Step 3

In a large saucepan melt butter over low heat and remove pan from heat. Whisk in brown sugar until dissolved and whisk in coconut cream, heavy cream, and lemon juice until combined well. Stir in flaked coconut and nuts.

　　

Step 4

Pour topping over shortbread. Reduce temperature to 325° F. and bake confection until top is golden and center is bubbling, 45 to 50 minutes. Cool confection completely in pan on a rack and cut into bars. Bars may be made ahead and kept, wrapped well, chilled 4 days or frozen 3 weeks. Serve bars chilled or at room temperature.