Sesame seeds are known as benne seeds in the South, and these cookies are a nod to traditional Southern benne wafers. The unconventional addition of tahini reinforced the nutty notes of the toasted sesame seeds, and browned butter brought richness and depth of flavor. We liked these made with a mixture of black and white sesame seeds. Black sesame seeds are sold in natural foods stores, Asian markets and in the international aisle of well-stocked supermarkets. Try to purchase seeds that are not pretoasted; if they are, use them straight from the package and toast only the white sesame seeds. If you cannot find black sesame seeds, you can make the cookies with just white. Turbinado sugar is a coarse raw sugar with a light golden color; it gives the cookies interesting texture as well as hints of molasses.