Soak oatmeal in buttermilk for 10-15 minutes. Mix the baking powder and baking mix together. Add to the oatmeal and mix well. Add more buttermilk, if necessary, to bring the batter to the thinness that you desire. Thicker batter will take longer to cook and may be more difficult to cook through.
Preheat griddle to medium heat or heat an electric frying pan to the temperature recommended for pancakes. Grease lightly with cooking spray.
Cook by 1/4 cupfuls on griddle, until golden brown on one side and bubbles are formed around the edges. Turn and cook on second side until golden brown.