Melt chocolate chips and shortening over a double boiler or in the microwave. In a bowl using a mixer, combine the eggs, sugar and vanilla until smooth texture is achieved. Add melted chocolate to the egg mixture with the mixer on low speed. Add flour, salt and baking soda.
Chill mixture for approximately one hour. Hand-form dough into two-inch rounds and place on parchment-lined baking sheets. Bake for roughly 15 minutes until slightly firm and crackles form on top. Remove from oven and top with three to four mini-marshmallows or half of a regular-size marshmallow. Return to oven and bake for 1 to 2 minutes. Transfer to a cooling rack.
This recipe is from the Cape Cod Cookie Company and also appeared in the 2013 May issue of Cape Cod LIFE.