Soak oats in buttermilk in a small bowl for 15 minutes. Combine all-purpose flour, whole-wheat flour, 1/4 cup sugar, baking soda, baking powder, salt, and 1/2 teaspoon ground cinnamon in a medium bowl. Whisk eggs together with egg whites in a small bowl, and stir in milk. Add the dry ingredients to the wet ingredients, and stir. Heat a nonstick skillet over medium-high heat, and coat with cooking spray. Pour about 1/2 cup batter per pancake onto hot skillet, and cook 2 minutes or until tops are covered with bubbles and edges look cooked. Flip and cook 2 minutes or until bottoms are lightly browned. Transfer to a plate; keep warm. Cook remaining batter in batches. Meanwhile, combine blueberries, 1/4 cup sugar, and lemon juice in a medium saucepan. Cook over medium heat until berries pop. Stir in 1/4 teaspoon ground cinnamon. Spoon blueberry sauce over pancakes; serve.