396-432gramsMars bars 11-12 snack size bars cut in half lengthwise
Cream your butter and sugars together until they are light and fluffy.
Add in the eggs, one at a time, beating in completely after each addition.
Add the vanilla and mix in.
Whisk together your dry ingredients and add to the butter/sugar mixture. Combine well then add the chocolate chips, mixing until they are spread through the dough evenly.
Take half of the cookie dough and press into the bottom of a pre-seasoned cast iron skillet.
Take the cut up Mars bars and place into the skillet, making sure they are distributed evenly across the surface of the cookie dough.
Take the remaining cookie dough and cover the Mars bars, filling in the spaces all the way to the skillets edge, making a smooth top. If you are using a 10 inch skillet, using all the cookie dough will bring the cookie right up to the top of the skillet. If you are using a 12 inch, it will be just below the skillet's edge. Both are lovely, but choose your size depending on the look you wish to achieve.
Bake in a 350 degree oven for 30-35 minutes, until the cookie is baked through.
Serve warm, cutting into pie shaped wedges and top with vanilla ice cream if desired.