Preheat the oven to 350 degrees Fahrenheit.Spray 2 small ramekins with non-stick spray. (If you use mini ramekins, you'll get 3 servings. If you use regular sized small ramekins, you'll get 2 large servings.) Set ramekins aside.Add the oats, flax meal, coconut flour, stevia (or maple sugar/syrup), baking powder, and cinnamon to a bowl. Stir the ingredients together and sift well.Next, add in the applesauce, almond milk, and vanilla to the dry ingredients until everything starts to come together to a thick batter consistency, much like a thick muffin batter. If your mixture looks a little dry, just add a couple tablespoons of water or more non-dairy milk.Now fold in the apples (and pecans if using) and stir the mixture until just combined.Finally, add the vinegar to the mixture last. The vinegar will react with the baking powder and help the baked oatmeal rise just like eggs do (don't worry, the vinegar flavor cooks off). Stir again just to incorporate.Place the ramekins on a baking sheet/pan for 30-35 minutes or until golden brown on top a fork comes out clean.Let them cool for 5 minutes and serve. You can also keep these in the fridge for up to a week as well.