Combine oats and buttermilk in a bowl. Cover and refrigerate overnight. Add the oil, beaten eggs and apple to the oat mixture and gently mix until combined. Combine the flour, baking soda, baking powder and salt in another bowl, and then mix into oat mixture until just combined. Heat a non-stick griddle or large non-stick pan, lightly brushing or spraying either with a little vegetable oil, to or over medium-high heat. Pour on 4-inch round pools of batter. Cook pancakes 2-3 minutes per side. Keep pancakes warm in a 200 degrees F oven until all are cooked. Serve with butter and applesauce or maple syrup.