Preheat oven to 375 degrees F. Line muffin pans with paper liners or coat with cooking spray. Set aside.In a large bowl, whisk together flour, cinnamon, baking powder and salt.Create a well with flour and add eggs, maple syrup, coconut oil and applesauce. Stir until flour disappears. Do not over stir. Gently fold in the diced apples. Set aside.In a small bowl, combine oats, flour, sugar, and cinnamon. Mix in coconut oil.Fill 12 muffin cups evenly and almost full. Sprinkle each muffin with oat streusel topping. Slightly press streusel into batter. Bake for about 20 minutes or until a toothpick stuck in the middle comes out clean. Let cool for 5 minutes. Enjoy!