Optional: 1/4 cup semi-sweet chocolate chunks or chips, melted
Instructions
Preheat oven to 350°F. Spray a 9″ pie plate (or cake pan or springform pan) with nonstick cooking spray and set aside.
In a large mixing bowl, mix together the flour, graham cracker crumbs, baking soda, and salt. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, or in a large mixing bowl using a hand-held mixer, cream the butter, brown sugar, and granulated sugar together until light and fluffy. Mix in the egg and vanilla, making sure to mix well after each ingredient. Slowly mix in the dry ingredients until just combined, scraping down the sides of the bowl as needed. Add in the chocolate chunks and mix until just combined. Scoop the cookie dough into the prepared baking dish and smooth it out into one even layer.
Bake at 350°F for about 25 minutes or until the top is set and lightly browned. Remove from the oven and transfer to a wire rack to cool for at least one hour, but it’s best to let it cool completely.
Just before serving, top with the mini marshmallows, return to the oven and broil until the marshmallows are lightly golden brown. Remove from the oven, slice, and enjoy.