Diamond Cookies: The Reason People Walk Out With Two Bags

Diamond cookies are French shortbread, edged in coarse sugar, sliced thick. The dough is mostly butter, there's no way around that and no reason to want one.
We bake them until the edges crackle and the centers stay tender. They keep beautifully, they ship beautifully, and they will absolutely become the cookie you bring to dinner parties.
Don't say we didn't warn you about the second bag.
