FOR THE CHOCOLATE CHIP COOKIE DOUGH
1 c. butter, softened
3/4 c. brown sugar
1/4 c. sugar
2 large eggs
1 tbsp. pure vanilla extract
1 tsp. baking soda
1 tsp. kosher salt
2 c. all-purpose flour
2 c. chocolate chips
FOR THE BROWNIE COOKIE DOUGH
1 box brownie mix
1 c. all-purpose flour
3 large eggs
1/3 c. plus 1 tbsp. melted butter
Preheat oven to 350° and butter a 12” cast-iron skillet.
In a large mixing bowl, cream butter and sugars until combined and fluffy, 2 minutes. Add eggs and vanilla and mix until combined.
Stir in baking soda, salt and flour, then add chocolate chips.
In a second large bowl, whisk together brownie mix and flour. Stir in eggs and butter until combined.
Transfer chocolate chip cookie dough to skillet and form the yin of a yin yang symbol, using your hands to shape the dough. Add brownie dough and shape the yang. Using a small biscuit or cookie cutter, cut a hole in each and swap the doughs.
Bake until golden, 25 minutes, then let cool slightly in skillet.
Serve slices with a scoop of vanilla ice cream and a drizzle of chocolate syrup.