Preheat the oven to 300F and line a baking sheet with parchment paper lightly sprayed with nonstick spray.
In a bowl whisk together the flour, cocoa, baking powder, cinnamon, and salt - set aside.
In a separate bowl whisk both sugars, eggs, milk, and vanilla until smooth Stir in the flour mixture, mix until well combined.
Melt the dark chocolate chips with the butter, either in the microwave or in a pan over medium heat stirring until smooth then add to the batter.
Fold in the milk chocolate chips.
Scoop out onto the line baking sheet and bake for 16 minutes or until cookies are set.
Remove from the oven and immediately top with a few mini marshmallows, the heat from the cookies should allow the marshmallows to stick to the tops. Alternatively, you could place the marshmallows on the cookies 1 min before they are done baking, this will give you more of a melted marshmallow on top.
Keyword chocolate cookies, cookies, double chocolate hot cocoa cookies, hot cocoa cookies