INGREDIENTS
1
boxed brownie mix, baked according to package directions (I used Ghirardelli Double Chocolate!)*
3/4 cup
unsalted butter, softened
1 cup
brown sugar
1/4 cup
granulated sugar
1
egg
2 tsp
vanilla extract
2 cups
all purpose flour
2 tsp
cornstarch
1 tsp
baking soda
1 tsp
salt
1 cup
bittersweet chocolate chips