• Preheat oven to 350º F and grease a 12 inch cast iron skillet

Make the Brownie Batter

• in a mixing bowl combine the very soft (even melted 1 cup butter will work), 1 cup sugar, 2 eggs and 1/2 teaspoon vanilla together until well mixed
• add the 1 1/2 cup flour, 1/3 cup cocoa, and 1/2 teaspoon salt to the butter, sugar mixture and mix until combined together.
• melt the 1 cup semi sweet chocolate chips in a microwave safe bowl for about 40 seconds, stir until smooth, then pour and mix into the brownie batter. Mix quickly so the chocolate doesn't harden.

Make the Cookie Dough

• just like the brownie batter, start by creaming together the softened 1/2 cup butter, 1/4 cup sugar, 1/2 cup brown sugar, 1 egg, and 1 teaspoon vanilla until combined.
• to the same bowl add in the 1 1/2 cups flour, 1/2 teaspoon baking powder, 1/4 teaspoon baking soda, and 1/2 teaspoon salt. Continue to mix by hand or with an electric blender until a soft dough is formed.
• mix in the 1 cup semi sweet chocolate chips, making sure to scrape the sides and bottom of the bowl to incorporate all of the ingredients.

Prepare For Baking

• make sure your cast iron skillet is greased before scooping the dough into the skillet. Scoop equal sized portions of cookie dough and brownie batter randomly in the bottom of the skillet. Spread the dough on the bottom of the pan, add any additional brownie or cookie dough on top.
• Bake for 35-40 minutes until a toothpick comes out clean or the dough doesn't jiggle if you shake the pan.