Gather the ingredients. Preheat the oven to 300 degrees F (150 degrees C). Line a baking sheet with parchment paper.

Combine butter, ½ cup sugar, rosemary, salt, and vanilla extract in a large bowl using the back of a spatula or spoon, slowly incorporating ingredients until butter has softened somewhat and ingredients come together.

Rub flour into butter mixture, using floured hands and fingertips, rubbing mixture together, until floury crumbs become buttery crumbs, about 1 to 2 minutes. Press mixture together until forms a dough ball.

Transfer dough to a lightly floured work surface; press into a disk, then into a ½-inch-thick rectangle. Cover with a piece of plastic wrap. Flatten dough to ¼-inch-thick using a flat pan or rolling pin. Reshape into a 5x12-inch rectangle.

Cut dough lengthwise into 5 even strips, about 1-inch wide, trimming excess dough if necessary. Cut each strip into 6 even squares (you can roll out scraps to form more cookies if necessary). Transfer cookies to the prepared baking sheet. Sprinkle each cookie with 1 pinch sugar. Poke 4 rows of holes into each cookie using a fork.

Bake in the preheated oven until golden brown, about 50 minutes.