Ingredients
1 box (18 to 18.4 ounces) brownie mix
¼ cup all-purpose flour
¼ cup vegetable oil
2 large eggs
½ cup semi-sweet chocolate chips (optional)
Instructions
Step 1 – Preheat and Prepare
Position an oven rack in the center of your oven and preheat it to 350°F (175°C) . Line two large baking sheets with parchment paper or silicone baking mats. This is crucial to prevent the fudgy cookies from sticking.
Step 2 – Combine Wet Ingredients
In a large mixing bowl, whisk together the vegetable oil and the eggs until they are well combined and slightly frothy.
Step 3 – Mix the Dough
Add the brownie mix and the flour to the bowl. Stir with a sturdy spoon or a rubber spatula until a very thick, stiff dough forms. The dough will be quite dense—this is exactly what you want. Mix until all the dry ingredients are fully incorporated and no streaks of flour remain. If your brownie mix does not already contain chocolate chips, fold in the ½ cup of chips now.
Step 4 – Portion the Dough
Using a cookie scoop or a spoon, portion the dough into balls of about 2 tablespoons each. Roll them lightly between your palms to form round balls. Place the dough balls on the prepared baking sheets, spacing them about 3 inches apart to allow for spreading. For a more decorative look, gently press a few extra chocolate chips into the tops of each dough ball.
Step 5 – Bake the Cookies
Bake the cookies in the preheated oven for 10 to 12 minutes. The cookies are done when the edges are set and firm, but the centers still look slightly soft, puffed, and a little underdone. Do not overbake, as they will continue to set as they cool.
Step 6 – Cool and Set
Remove the baking sheets from the oven. Let the cookies rest on the baking sheet for at least 10 to 15 minutes. This resting period is essential for the fudgy centers to firm up. After resting, transfer the cookies to a wire rack to cool completely.