Step 1

Preheat the oven to 325°F. Gently spray a 9x13-inch baking pan with nonstick spray and line the pan with parchment paper. (See notes for tips on how to best cut the parchment paper and line the dish.)

Step 2

In a large mixing bowl, combine the butter and powdered sugar using a fork or electric hand or stand mixer. Blend for 2 to 3 minutes until the mixture is smooth and fully combined. Add the vanilla and salt and blend again. Add 1/3 to 1/2 of the flour and blend until incorporated. Continue adding the rest of the flour in batches and mixing until all the flour is incorporated and smooth. The dough should be thick and velvety.

Step 3

Transfer the dough to the prepared baking pan and press it flat with your hands. Be sure to press across the entire surface and toward the corners. Place another sheet of parchment paper on top of the dough and rub your hands, a small rolling pin, or a flat-bottomed glass over the parchment to further smooth the dough and create a perfectly flat surface. Remove the top parchment piece.

Step 4

Bake the shortbread in the preheated oven for 20 minutes. After 20 minutes, remove the pan from the oven, but keep the oven on.

Step 5

Using a sharp knife, make 5 even cuts parallel to the length of the pan, dividing the shortbread in 6 equal strips (the strips should be about 1 1/2 x 13 inches). Then make 2 even cuts parallel to the width of the pan, dividing each long strip into thirds. This will make 18 pieces of shortbread, each about 1 ½ x 4 inches.

Step 6

Gently press the tongs of a fork into each piece of shortbread, forming two parallel lines of equally spaced holes. These holes will create the traditional Walker’s look.

Step 7

Return the pan to the oven and continue to bake for 8 to 9 minutes. Remove the pan from oven and allow the shortbread to cool completely before enjoying.