In a small bowl, combine non dairy milk, instant espresso and vanilla. Stir to combine and set aside.
5 tablespoon Non-Dairy Milk, 2 teaspoon Instant Espresso Powder, 2 teaspoon Vanilla Extract
In a large bowl using a wooden spoon, or in the bowl of your stand mixer fitted with the paddle attachment, cream the butter and brown sugar until creamy and well combined.
8 tablespoon Non-Dairy Butter, room temperature., 1 Cup Light Brown Sugar, tightly packed
Add the non-dairy milk mixture and mix until well combined. The mixture will look broken, here and that's okay.
Add the cocoa powder and mix until well combined. Then, add flour, baking powder, baking soda and salt. Mix until just combined.
½ Cup Dutch Processed Cocoa Powder, sifted, 1 ½ Cups All Purpose Flour, 1 teaspoon Baking Powder, ½ teaspoon Baking Soda, ½ teaspoon Kosher Salt
Add chocolate chips and mix just until they are distributed.
1 Cup Dark Chocolate Chips
Use a 4-tablespoon cookie scoop to scoop all of the dough onto a parchment-lined baking sheet. You should get 12 mounds of dough. Cover and place in the refrigerator to chill for one hour.
Preheat oven to 350* F. Line a sheet tray with parchment.
Working one at a time, make a well in a mound of dough and place 4-5 mini marshmallows into the well. Then, cover the marshmallows with the dough and gently roll the dough into a sphere with the palms of your hands.
¾ Cup Mini Marshmallows
Repeat until all the cookies are stuffed with marshmallow.
Place 6 dough balls on a cookie sheet, leaving at least 2 inches of space between each. Gently press the balls down to keep them from rolling around.
Bake in a 350* oven for 17-19 minutes or until the edges of the cookies are set.
Allow the cookies to cool on the baking sheet for at east 5 minutes before moving to a wire cooling rack to cool completely.
Repeat with the remaining cookie dough balls.
Cool slightly, serve.