Preheat oven to 350º. Cream together coconut oil, sugar, and applesauce in a stand mixer on low speed (or if by hand, using a medium mixing bowl and electric beaters).
Add flour, cocoa, baking soda, baking powder, and pink salt; beat until combined well. Mixture should be wet and sticky- if it's crumbly or dry, add 1 tablespoon of applesauce. Stir in chocolate chips and mixed nuts, beat for 30 seconds.
Spoon onto baking sheets lined with parchment paper. 1 tablespoon per cookie will give you approximately 50 mini cookies, totaling 25 sandwich cookies to finish.
Bake 7 min and remove from oven. Top half of your cookies with 3 mini marshmallows each, and sandwich together with remaining cookies. I used a spatula to gently press down on each one, to help hold in place. Return trays to oven and bake an additional 3 minutes more. Enjoy!