Preheat oven to 350 degrees
Grease jumbo muffin pan with non-stick cooking spray.
In a large mixing bowl, prepare brownie mix according to directions on package. Fold in ¼ cup graham crackers, ¼ cup marshmallows and half of the chopped chocolate bar.
Divide the brownie mixture evenly among 12 muffin cups. (I used a #16 scoop to portion out the brownie batter.)
In a medium mixing bowl, prepare cookie dough according to instructions on package.
Using two spoons, drop thin pieces of cookie dough on top of the brownie mixture.
Bake on the center rack for about 25 minutes or until the center of cookie dough is browned and set and a toothpick comes out clean.
Remove from oven and let cool for 10 minutes in muffin tin. Press tops with bottom of glass dish or bottom of muffin tins to create a bowl shape.
Top the rookie bowl with graham crackers and marshmallows. Broil for 2-3 minutes until marshmallows are golden brown.
Remove from oven and top with chocolate bar.
Release from pan by running a butter knife along the outside of the brookies. Serve warm or cool on a wire rack and place in a Ziploc bag until ready to serve.
Optional: Garnish with a large scoop of ice cream and toppings of choice.