Instead of using both the broiler and baking method, you can simply bake the cookies at 400 F / 200 C in the upper third of the oven for about 15 to 20 minutes, or until lightly colored with cracked tops.
How dark to make the cookies is up to you. Traditionally, most shortbread recipes require baking until set and barely colored, but many Moroccans consider pale cookies to be underbaked. These should be baked long enough to achieve a dry crumb at least, but many cooks prefer to continue baking to a golden hue. Take care not to burn them.
If using the specially molded pan, the dough may be shaped into flatter discs (be sure the edges aren't cracked) with thinner edges to achieve a more dramatic hollowed-out bottom.
If time allows, bake a few test cookies to see how your dough reacts in your oven. My current oven, for example, heats differently than other ovens I've had, requiring that I bake cakes, cookies, and bread in the upper third of the oven rather in the middle.