Step 1: Preheat your oven to 350°F (175°C) for even baking.
Step 2: In a large mixing bowl, combine vegetable oil, dark brown sugar, and granulated sugar. Whisk until blended, then add apple sauce and vanilla extract, mixing until smooth.
Step 3: In another bowl, whisk together flour, cinnamon (if using), baking soda, and salt. Gradually add to the wet mixture, stirring until just combined.
Step 4: Fold in the rolled oats and dark chocolate chips using a spatula until evenly distributed.
Step 5: Using a cookie scoop or tablespoon, drop dough onto lined baking sheets, keeping enough space for spreading. Bake for 12-15 minutes until edges are golden.
Step 6: Let cookies cool on baking sheets for a few minutes before transferring to a wire rack. Enjoy your cookies warm or at room temperature!
