Using the paddle attachment on a stand mixer, beat the butter until creamy.

Scrape down the bowl with a rubber spatula.

Add the parmesan cheese, flour, salt, rosemary, and pepper. Beat until it comes together into a ball and pulls away from the sides of the bowl. (a few loose crumbs remain)

Turn the dough out onto a large sheet of plastic wrap, knead it a few times until smooth ball forms without any major cracks, and roll it into a 10-inch log. **See notes**

Wrap the log tightly in plastic wrap and freeze for at least 30 minutes, or until firm. We like to refrigerate the dough overnight. The flavors are so much better.

Preheat the oven to 350ºF.

Slice the log into roughly 1/4- to 1/2-inch pieces (make sure they're all the same thickness). Place the dough slices about an inch apart on the half-sheet pan and bake for 16 to 22 minutes (depending on their thickness), or until firm and golden brown.