Tender Shortbread Cookies (pan-style)

Ingredients

• 1 cup [2 sticks or 227 g] unsalted butter, at room temperature
• 2/3 cup [130 g] granulated sugar, plus more for sprinkling
• 1/3 cup [40 g] confectioners' sugar
• 1 teaspoon fine salt
• 2 large egg yolks
• 2 teaspoons pure vanilla extract
• 2 cups [284 g] all-purpose flour

Instructions

1. 1

   Adjust an oven rack to the middle of the oven. Preheat the oven to 300F [150C]. Grease and line a 9 in [23 cm] square baking pan, see note.

2. 2

   In the bowl of a stand mixer fitted with a paddle, beat the butter on low speed until creamy, about 1 minute. Add the granulated and confectioners' sugar and salt, and beat again until creamy and combined, 2 to 3 minutes. Add the egg yolks and vanilla and mix again until combined, one minute. Add the flour and and mix on low until completely combined.

3. 3

   Move the dough to the prepared pan, and spread the dough into an even layer across the bottom of the pan. Spreading a piece of plastic wrap over the top of the dough helps with moving it and keeping it from sticking. Sprinkle the top with granulated sugar.

4. 4

   Place the shortbread in the oven and bake until the shortbread is pale golden and firm to the touch, 35 to 50 minutes (see notes). Remove the pan from the oven and sprinkle the top with more granulated sugar if desired. Let the shortbread cool for 15 minutes in the pan. Use the parchment sling to carefully remove the shortbread, then cut the warm shortbread into rectangle pieces. I cut the piece in half horizontally, and then cut each half into 6 rectangles. Let the shortbread cool for several hours. Shortbread can be stored in an airtight container at room temperature for 4 to 5 days.