Tender butter cookies with a soft thumbprint center, finished with a simple rum icing and a light dusting of nutmeg.
Store the cookies in an airtight container at room temperature for up to 3 days, or refrigerate for up to 1 week. If stacking, place parchment paper between layers so the icing stays neat. If the dough feels too soft to shape, chill it for 10 minutes before rolling. If the thumbprint puffs up while baking, gently press the center again while the cookies are still warm. These cookies do not need reheating. For the best texture, let chilled cookies sit at room temperature for 15 to 20 minutes before serving. To freeze, place the finished cookies in a single layer until firm, then transfer to a freezer safe container with parchment between layers. Freeze for up to 2 months and thaw in the refrigerator or at room temperature.