These walnut shortbread cookies are built on a simple, buttery shortbread base, upgraded with toasted walnuts and a touch of instant espresso that adds subtle roastiness without overpowering the cookies.
Roast the walnuts - In a skillet over medium heat, roast the walnuts for 3 – 5 minutes until toasty and fragrant. Spread the nuts on a cutting board to cool and then chop into small pieces.
1 cup walnuts
Prepare the dry ingredients - Sift flour, cornstarch and instant espresso powder into a small mixing bowl, stir to distribute evenly.
Cream butter and sugar together - Add softened butter, vanilla, sugar and salt to a stand mixer bowl fitted with the paddle attachment. Beat on medium speed until the mixture is thoroughly incorporated and creamy.
8 oz unsalted butter, ⅔ cup granulated sugar, ¼ teaspoon kosher salt, 1 teaspoon pure vanilla extract
Add dry ingredients - Add the flour mixture and chopped walnuts to the creamed butter, stir to combine. Increase the mixer speed and beat until no trace of flour remains and the dough is formed.
Form the logs - Place a long piece of plastic wrap flat on the countertop. Divide cookie dough into 2 equal portions. Roll each portion on top of the plastic wrap into a log about 6” in length. Wrap well and refrigerate for at least 1 hour before baking. You don’t need additional flour for rolling but you can use some flour if necessary.
Slice the cookies - Use a sharp knife to slice each cookie dough log into 12 cookies about ½” thick. Rewrap in the same plastic and place them into the freezer for 15 - 30 minutes, while the oven preheats.
Preheat the oven - Set the oven rack in the middle of the oven and preheat to 350°F.
Bake - Place 12 cookies on a large lined baking sheet, about 2 inches apart. Sprinkle granulated sugar on top of cookie dough and bake 1 batch at a time for about 22 minutes, until the outer edges of the cookies are golden.
Extra granulated sugar for topping
Cool - Remove the baking sheet from the oven, but allow the cookies to sit on the baking sheet to finish baking from the residual heat for 5-10 minutes before removing them to a wire rack to cool completely.
Notes
Storing baked cookies: store your pecan shortbread cookies in an airtight container at room temp for up to a week.
Storing cookie dough: cookie dough can be kept refrigerated for 3-4 days before baking to prep ahead. Or slice and freeze for 3-6 months.
Baking frozen dough: no need to thaw frozen cookie dough, you can bake directly from the freezer.