Drop spoonfuls on a baking sheet lined with parchment paper. Use the back of a spoon to smooth out into even circle shapes.
Bake 9-11 at 375 degrees or until toothpick comes out clean in the center. Allow to cool on a wire rack.
Filling
Turn oven down to 350. Place whoopie pies upside down on a baking sheet with 1 marshmallow in the center of each cake.
Place in oven and turn the oven off. Allow marshmallows to sit for about 2-3 minutes or until just beginning to become soft and puffy.
Immediately remove from oven and sandwich together.
Notes
While lovely to look at and share, these do not freeze or keep well. Best to enjoy right after assembly. This treat is best used for helpers in the kitchen to be enjoyed immediately after baking. Even transporting can be tricky due to the sticky nature of marshmallows. You've been warned. ;-)
Recipe by Petite Allergy Treats at https://petiteallergytreats.com/gluten-free-whoopie-pies-with-marshmallow-egg-free/