Preheat the oven to 350 degrees F. Line a baking sheet with parchment paper. In a large mixing bowl, or the bowl of a stand mixer, mix the canola oil, peanut butter, eggs, and vanilla until combined. Add the oatmeal, flour, brown sugar, granulated sugar, baking soda, and salt. Beat until the dough is moist and all the ingredients are combined. The dough will be crumbly. Mix in the chocolate chunks.Using your hands, clump together about a tablespoon of dough at a time and squeeze into a ball. Place on the prepared baking sheet 2 inches apart and very gently flatten with the palm of your hand just slightly. The dough will be crumbly, this is OK.Bake for 8 to 10 minutes, or until set and golden. These are crumbly cookies, so let them cool 5 minutes on the pan, then enjoy!