1) Combine oats, flour, baking soda, baking powder, and salt in a bowl. In a separate medium-sized bowl, whisk buttermilk, eggs, oil, maple syrup or honey, and vanilla extract together. Add dry ingredients to this wet mixture and stir until mostly blended.
2) Refrigerate overnight.
3) Heat a large skillet over medium heat and spray with non-stick cooking spray. Ladle batter into small pancakes and cook until bottom is golden brown and you see bubbles on top. Flip with a spatula and cook until the bottom is golden brown.
4) Serve with fresh or frozen fruit (i.e. berries or peaches) cooked down in a fruit sauce. Use real maple syrup or raw honey (not for babies) to sweeten fruit sauce to taste. Top with slightly sweetened plain Greek yogurt (optional).