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.
Notes
Make sure you use quick oats. They absorb liquid quicker. Regular oats can result in a very thin batter. If your batter is too thin, let it sit for a few minutes till it thickens up.