Combine first 6 ingredients in a large bowl and mix well. Gently stir in remaining ingredients. Let stand 10 minutes without stirring.
Mix batter briefly and make a test pancake by dropping a large spoonful of batter onto a medium-hot oiled griddle or nonstick skillet. Cook until underside is lightly browned. Flip with a spatula and cook other side. Adjust consistency of batter, if necessary, by adding a little more flour or milk.
Cook remaining pancakes. Serve hot with butter and maple syrup or preserves.
Note: Be sure to use quick-cooking rolled oats, not old-fashioned or instant oats.