Set your oven to 350 degrees.
In a large bowl combine your cake mix, brown sugar, and cocoa powder.
Add in your eggs and oil and mix until everything is combined.
Add in your marshmallows and pecans/walnuts and just stir them in until incorporated.
Line your baking sheet(s) with parchment paper or a silicon mat.
Scoop out 1-2 Tbsp. of dough and drop onto your baking sheet 2 inches apart. These will spread so make sure there is room. I did 5 per sheet but you could probably fit a few more than that.
Bake for 10-11 minutes until they are set. I added on top a marshmallow or two to the cookies at 2 minutes left to melt on top. (
Many of the marshmallows melt inside the cookie when baking so I wanted to add some more of that taste/texture by adding additional ones on top either 2 minutes until finished baking or right after they come out of the oven.)
Let cool for 5-10 minutes.
