Makes 36 cookies
8 ounces (16 tablespoons) unsalted butter, chilled, cut into 1/2-inch pieces
1/2 cup granulated sugar
2 cups all-purpose flour
Pinch of kosher salt
Combine the butter and sugar in the bowl of a stand mixer fitted with the paddle attachment and beat on low speed until the butter and sugar begin to incorporate, about 15 seconds. Add the dry ingredients and continue to mix until the dough comes together, about 3 minutes. It will look dry just before it comes together.
Line 2 baking sheets with parchment paper. On a lightly floured work surface, roll out the dough 1/4 inch thick. Using a 2-inch star cutter or other shaped cutter, cut out as many cookies as possible. Gather together the scraps, reroll, and cut out more cookies. You should have about 24 cookies. Place the cookies on the prepared baking sheets, spacing them 1 inch apart. Refrigerate until firm, at least 1 hour.
Preheat the oven to 300 degrees.
Bake the shortbread until firm, about 35 minutes.