For the Brownie Layer:

1 box brownie mix (plus ingredients required on the box)
For the Cookie Dough:

1/2 cup unsalted butter, softened
1/2 cup granulated sugar
1/2 cup light brown sugar, packed
1 tsp vanilla extract
2 tbsp milk
1 1/4 cups all-purpose flour
1/2 tsp salt
1 cup mini chocolate chips
For the Chocolate Coating:

12 oz semi-sweet chocolate chips
1 tbsp vegetable oil