Preheat the oven to 375°F. Line 2 baking sheets with parchment paper or silicone baking mats. Whisk together the dry ingredients in a large bowl and set aside.

Cream butter and sugars: Place the butter and sugars in the bowl of a stand mixer. Secure the paddle attachment and blend until incorporated ~2-3 minutes. It will look like a paste.

Then, add in the egg, egg yolk, and vanilla extract. Blend until mixed.

Turn the mixer to low speed and gradually add in the dry ingredients, mixing just until incorporated.

Add in 6 graham crackers, Hershey's chocolate, and chocolate chips until incorporated and then turn off the machine.

Measure out the cookies into ~7-8, ~5 oz. portions. Make a well in the center of the cookie with your thumbs, fold dough over marshmallow. Decorate cookies and place on prepared baking sheets.

Bake at 375°F for 10-13 minutes or until tops are golden brown. Let cool for at least 15 minutes. Garnish with flaky sea salt on top (optional) and enjoy!