These uber-thin, crispy buttery sugar cookies have a piney rosemary aroma and flavor with a crunchy sugar rim. They'll go quickly, better make a double batch.
Add softened butter and sugar to a large mixing bowl and beat together until light and fluffy, about 2 minutes.
Add the flour and salt and mix on low speed until the flour is incorporated.
Add the chopped rosemary and mix into the dough with a rubber spatula. Dough should be thick, but workable.
Roll the dough into a cylinder shape and place it on the work surface. Roll the dough back and forth until you have a long rope about 2" in diameter.
Place a long piece of parchment (about 24") on a work surface and sprinkle a long line of decorating sugar in the center. Place the dough on the sugar and roll back and forth to coat all sides of the dough. You may have to sprinkle more sugar on in some spots to get coverage.
Roll the dough up tightly in the parchment paper and twist the ends to seal. Transfer the dough a baking sheet that will fit flat in your freezer. Place the dough on the baking sheet and freeze for 2 hours or overnight.
When you're ready to bake the cookies, preheat the oven to 350°. Line a baking sheet with parchment paper or a silpat and set aside.
Use a very thin, sharp knife to slice the cookies into ¼"-⅓" rounds. Transfer the cookies to the prepared pan. If desired, press one or two rosemary leaves onto the tops of each cookie.
Bake for 11-13 minutes. The cookies will still be soft when you remove them from the oven and may not look done, however, you want to pull them out of the oven BEFORE they start to brown. My cousin, Marisa usually cuts one cookie smaller than all the rest and places it on the cookie sheet -- and when the small cookie starts to brown, that's the sign that the rest of the cookies are done.
Let the cookies rest on the cookie sheet for about 5 minutes before transferring to a cooling rack. Store cooled cookies in an airtight container.