* Make-ahead: the mixture keeps covered in the refrigerator for 2 days, or scoop the shaped mounds onto a tray, freeze them solid, and bake from frozen with 2 extra minutes.
* Storage: an airtight tin at room temperature keeps them for 5 days, with parchment between the layers. Do not refrigerate, which dries the coconut out. Baked cookies freeze for up to 3 months.
* Substitutions: unsweetened coconut works with 2 extra tablespoons of condensed milk, and sweetened condensed coconut milk makes the whole batch dairy-free.
* Doneness: judge by the golden edges rather than the center. The tops should still look pale and soft when you pull the sheet out.
* Nutrition values are an estimate.