Preheat the oven to 375°F. Line 2 baking sheets with parchment paper.
In the bowl of a stand mixer fitted with the paddle attachment, add the butter, brown sugar, and vanilla extract. Mix on low until combined and there’s no butter are no butter chunks.
Add the eggs and mix for a few rotations, just to break the yolks.
Add the flour, cocoa powder, baking powder, and salt. Mix on low until combined.
Add the chocolate chips and graham cracker pieces and mix to combine completely.
Using your hands, form the dough into 12 balls and place on the prepared baking sheets, spacing evenly apart. You’ll have 6 cookies per sheet.
Using a tablespoon, press into the center of each cookie and fill it with marshmallow creme. Top with a little bit of crushed graham cracker crumbs.
Bake for 15 to 17 minutes or until the edges look dry and set. Be middle will look gooey still, that’s okay!
I like to round them out with a cookie cutter for perfectly round cookies immediately after coming out of the oven. Allow to cool completely on the baking sheets.
Store in an airtight container for up to 3 days.