Whisk together oats, flour, baking powder, soda, and salt in a small bowl. Set aside.In a large bowl, whisk together the brown sugar, eggs, oil, vanilla, and buttermilk. Lightly stir the dry ingredients into the buttermilk mixture. Pour or spoon batter onto a medium low skillet. Cook till lightly browned, then flip and cook on the second side. Serve hot with butter and syrup, or your choice of toppings.