Step 1: Preheat your oven to 350°F (175°C) and line two large baking sheets with parchment paper or silicone baking mats.
Step 2: In a large mixing bowl, combine the dry brownie mix, oil (or melted butter), and eggs. Stir with a sturdy spatula or wooden spoon until a thick, uniform dough forms.
Step 3: If using, fold in the chocolate chips or your favorite nuts until evenly distributed throughout the Brownie Mix Cookies dough.
Step 4: Using a small cookie scoop or a tablespoon, drop rounded portions of dough onto the prepared baking sheets, leaving 2 inches of space between each.
Step 5: Bake in the preheated oven for 8 to 10 minutes. The edges should be set, but the centers will still look soft and slightly shiny.
Step 6: Allow the Brownie Mix Cookies to cool on the baking sheet for at least 5-10 minutes before transferring them to a wire rack to cool completely.