Coffee-Meringue Acorns
It's fun to use pistachios for some of these and pecans for others, but of course you can stick with one or the other. It's best to bake them on a dry day; if it's even slightly humid, the meringues may take longer to crisp in the oven. The meringues can be made up to five days ahead and stored in a cool, dry place.
Martha Stewart Living, December 2013