Preheat oven to 350°F (175°C) and grease a 9x5 inch loaf pan.
In a large bowl, whisk together oats, flour, baking powder, baking soda, cinnamon, and salt.
In a separate medium bowl, beat eggs then stir in yogurt, maple syrup, applesauce, and vanilla.
Fold the wet ingredients into the dry ingredients until just combined.
Gently fold in the diced apples.
Pour batter into the prepared loaf pan and smooth the top.
Bake for 45 to 55 minutes, or until a toothpick inserted into the center comes out clean.
Allow to cool in the pan for 10 minutes before transferring to a wire rack.