Preheat oven to 350 F and line cookie sheets with parchment paper or a silicone baking mat.

Using a wooden spoon, combine oil, eggs, sugars and vanilla in a large mixing bowl.

Sift the dry ingredients (baking soda, salt, cinnamon, all-purpose flour) into the wet mixture.

Stir in the oats, along with the mix-ins of your choice into the cookie dough.

Use a medium cookie scooper to portion cookie batter onto the prepared baking sheets. If you don't have a cookie scoop, use a tablespoon to form small balls. Leave at least two inches around each ball, as these cookies do like to spread a little bit.

Bake oatmeal cookies in preheated oven for 12-15 minutes. Cool for 5 minutes on baking sheet, then remove to a wire rack to fully cool. Try not to eat the whole batch in one sitting.