In a bowl, cream butter with the brown and granulated sugars using an electric beater.
1 cup butter, softened, ¼ cup granulated sugar, 1/2 cup brown sugar
Mix in the flour and salt until incorporated, then mix in the pecans and rosemary, careful not to overmix or the cookies will become tough.
2 ¼ cups all-purpose flour, 1/4 tsp salt, 1 cup pecans, 1 tsp rosemary
Place the dough onto a lightly floured surface and press it into a rectangular shape using your hands.
Roll out the dough to between ¼ and ½ inches thick using a rolling pin. You can use your hands or a bench scraper to periodically straighten out the sides/edges of the dough so that it stays in a rectangular shape. Cut it into 24 rectangular or square cookies.
Wrap the dough in plastic wrap and chill in the refrigerator for at least 30 minutes or up to overnight.
When ready to bake, preheat the oven to 325°F and line a baking sheet with parchment paper. Remove the dough from the fridge and place the cookies on the baking sheet.
Bake the cookies for 16 minutes, or until you can just see the bottom edges of the cookies turning golden brown. Remove the cookies from the oven and let them cool completely before eating.