Double Chocolate Marshmallow Cookie Bars

0 Line a 13x9x2 baking pan with parchment paper and pre-heat oven to 350 F.
1 In a medium-sized bowl mix flour, cocoa powder, baking soda and salt. Set aside
2 Mix butter and sugars, until light and fluffy. Add vanilla extract, eggs and mix. Add dry ingredients and mix until just combined. Do not over mix. Fold in Chocolate chips.
3 Spread 2/3 of the cookie dough into your prepared pan; batter will be sticky, so either wet your fingers with water or use a piece of parchment paper to spread an even layer
4 Add dollops of the marshmallow fluff on top of the cookie layer, distributing them all over the pan, then spread them as evenly as possible (don't worry if not everything is covered!). Using your fingers, crumble the remaining dough on top of the marshmallow fluff layer, you want some marshmallow fluff picking out between the cookie crumbles. Add a few chocolate chips on top if desired
5 Bake for 22-25 minutes, or until a toothpick inserted in the middle comes out almost clean. Let cool completely over a wire rack. Cut in 24 bars and enjoy!