Heat oven to 350°F. In the bowl of a mixer, stir flour into brownie mix until well incorporated.
In a separate bowl, slightly beat eggs with the coconut oil and add to the mix along with chocolate chip and any other custom add-ins. Mix on low speed, or by hand, until the flour is moistened. The dough should be pretty stiff like cookie dough.
Place the dough in heaping tablespoons (about .80 ounces each) in on a parchment-lined baking sheet; this amount will spread to 2 1/2-inches when baked.
Bake for 10 minutes and allow the cookies to rest on the pan for 1-2 minutes after removing from the oven. Remove from the pan and cool on baking racks.
If you're a fan of the chewy edge pieces lining a pan of brownies, you'll want to follow the cooking time of the recipe just as it's written.
If you're more of the gooey middle brownie lover, reduce the baking time by 1 minute and see if that is closer to the brownie cookie you dream about.
Any 18 ounce brownie mix should work for this recipe, though I highly recommend Ghirardelli. NOTE: If using a 20 ounce mix, omit the extra flour and test 1 cookie in oven for shape. If the cookie spreads too much, mix-in 1-2 tablespoon of flour into the dough and retest.