Preheat oven to 425°F (220°C). Line or grease a 12-cup muffin tin.
In a large bowl, whisk flour, baking powder, baking soda, cinnamon, and salt. Stir in grated and diced apples.
In another bowl, whisk oil and maple syrup. Add eggs, yogurt, applesauce, and vanilla, mixing until smooth.
Gently fold wet ingredients into the dry until just combined. Do not overmix.
Divide batter evenly into muffin cups. Sprinkle with turbinado sugar.
Bake at 425°F for 5 minutes, then lower oven to 350°F (175°C) and bake another 10–12 minutes.
Cool in the pan for 5 minutes, then transfer muffins to a wire rack.