Whoopie pies are not so much a cookie as a cake-and-frosting sandwich, but they qualify in spirit. They are a treat closely associated with New England and Maine, in particular. They also have ties to Amish country. This version consists of two saucer-shaped rounds of chocolate cake around a marshmallowy cream filling.
Recipe notes: We preferred the smaller pies described here, but if you want a really decadent treat, you can use 1/4-cup scoops of dough to create the cakes. The yield will be 8 large sandwiches.
The cakes and filling can be made 1 day in advance and stored at room temperature in airtight containers. The cakes can be somewhat sticky, so store them in a single layer without touching. The assembled whoopie pies can be stored individually wrapped at room temperature for 1 day.
Marshmallow Fluff is a New England ingredient available in certain other parts of the country. Marshmallow creme, more widely available, is a thinner consistency than Fluff. If you make your filling with marshmallow creme, you may need to add a bit more sugar to stiffen it up sufficiently.
