Chocolate Peanut Butter Shortbread Squares

The milk-chocolate topping of these cookies looks like the result of masterful piping, but it's actually a cinch to make using a mold. Beneath the chocolate hides a layer of peanut butter on top of brown-sugar shortbread, all of them adding up to a treat that's creamy and crumbly and rich throughout.

Chocolate Peanut Butter Shortbread Squares

YIELD: Makes about 36 squares

Ingredients:

• Vegetable oil, cooking spray
• 2 cups all-purpose flour
• 1 1/4 teaspoons coarse salt
• 8 ounces (2 sticks) unsalted butter, softened
• 3/4 cup packed light-brown sugar
• 12 ounces milk chocolate, melted
• 1 cup creamy peanut butter

Cook's Note:

You will need a basket-weave mat (I used an 8"-by-16" rubber texture mat in basket weave (PA 01-6), $12, from chineseclayart.com) to imprint the chocolate with the woven motif. To make the squares without a mat, spread the melted chocolate atop the peanut butter layer, and refrigerate until firm, about an hour.

Instructions:

Coat a 9 1/2-inch square baking pan with cooking spray. Line with parchment, leaving a 2-inch overhang on 2 sides, and coat parchment with spray.

Sift flour and salt into a medium bowl. Beat butter with a mixer on medium-high speed until fluffy, 3 to 5 minutes. With the mixer running, add sugar, and beat until pale and fluffy, about 2 minutes. Reduce speed to low. Add flour mixture, beating until just incorporated. Press dough evenly into pan. Cover, and refrigerate until firm, about 20 minutes.

Preheat oven to 300 degrees. Bake shortbread until golden brown and firm in center, 45 to 50 minutes. Let shortbread cool in pan on a wire rack.

Place a basket-weave mat, trimmed to fit pan, on a rimmed baking sheet, and spread melted chocolate evenly on mat. Refrigerate until firm, about 45 minutes.

Use parchment to unmold shortbread from pan, and trim edges to create a square. Spread peanut butter evenly on shortbread. Carefully center chocolate, mat side up, on top of peanut butter, and gently peel off mat. Cut shortbread into 1 1/2-inch squares. Shortbread will keep, covered, for up to 3 days.