Warm, spicy notes of clove and nutmeg mingle with a pecan crunch in these tender cookies.
In a large bowl, whisk together flour, cornstarch, salt, nutmeg, and cloves; set aside.
In the bowl of an electric mixer fitted with the paddle attachment, beat butter and brown sugar together on medium speed until smooth, about 3 minutes. Add vanilla, and mix to combine. Add pecans. Reduce mixer speed to low and add flour mixture; mix until just combined.
Turn dough out onto work surface and form into two flat squares; wrap with plastic wrap and transfer to refrigerator. Refrigerate for at least 2 hours and up to 2 days.
Preheat oven to 350 degrees with racks set in the upper and lower thirds. Line two baking sheets with parchment paper; set aside.
Place a nonstick baking mat on work surface. Place one square chilled dough on baking mat; top with a sheet of plastic wrap. Roll out dough between baking mat and plastic wrap until it is 3/8-inch-thick. Transfer to freezer to chill until firm, about 30 minutes. Repeat process with remaining dough.
Using a 2 1/4-inch square cutter, cut out dough and transfer to prepared baking sheets. Carefully prick each cookie with a skewer, gently pushing through the dough until it reaches the baking sheet.
Transfer baking sheets to oven and bake, about 10 minutes. Halfway through baking, repeat pricking process and rotate baking sheets from top to bottom and front to back. Cookies should be very pale and not take on too much color. Transfer cookies to rack to cool.