#1 Preheat your oven to 350°F and line a baking sheet with parchment paper #2 In a large mixing bowl, cream together the softened butter, and both sugars until the mixture is light and fluffy #3 Beat in the eggs one at a time, ensuring each egg is fully incorporated before adding the next. Stir in the vanilla extract #4 In a separate bowl, sift together the flour, cocoa powder, baking soda, and salt #5 Gradually add the dry ingredients to the wet ingredients and mix until just combined #6 Gently fold in the semisweet chocolate chips and mini marshmallows into the cookie dough #7 Scoop spoonfuls of dough and roll them into balls. Place them on the prepared baking sheet, leaving enough space between each cookie #8 Bake in the preheated oven for 10-12 minutes, or until the cookies are set but still soft in the center. The marshmallows should be golden and slightly gooey #9 Allow the cookies to cool on the baking sheet for a few minutes, then transfer them to a wire rack to cool completely. Enjoy!