Preheat your oven to 375°
Melt your butter on medium heat until brown. This should take about 5 minutes. Be sure to stir often and keep an eye on it so it doesn't burn. Once it has browned, pop in the freezer to bring it back to a solid, but soft state.
In a medium bowl, combine your flour, crushed graham cracker crumbs, salt and baking soda. Whisk until combined.
Place your brown butter into a mixing bowl and whisk in the sugars until incorporated. Add in vanilla extract and egg. Whisk until all combined.
Fold in your dry mixture until its well incorporated and a dough starts to form. Next, fold in your chocolate chips.
Lay your marshmallows on a sheet pan lined with parchment paper. Using your measuring cup, scoop out your dough and cover your marshmallow. Form a ball around the marshmallow and press down a bit too secure. Sprinkle with flake salt (optional) Bake for 12-14 minutes. Enjoy!