Preheat the oven to 350°F (175°C). Prepare a baking sheet by either lining it with parchment paper or applying a thin layer of grease to prevent sticking.
In a spacious mixing bowl, combine the boxed cake mix with the eggs and oil. Stir the ingredients together thoroughly until a smooth, cohesive dough forms without any visible dry patches.
Gently incorporate the chocolate chips or other selected additions, folding them evenly throughout the batter.
Portion the dough using a tablespoon, spacing each mound about 2 inches apart on the prepared baking sheet to allow for spreading during baking.
Place in the oven and bake for 10 to 12 minutes, or until the edges are firm and lightly golden while the centers remain slightly soft to the touch.
Allow the bars to rest on the baking tray for 2 to 3 minutes post-baking before relocating them to a wire cooling rack to cool completely.