Preheat oven to 250°.
Combine first 6 ingredients in a large bowl, stirring well to combine.
Melt 2 tablespoons butter in a medium saucepan over medium heat. Add 1/3 cup applesauce, honey, and brown sugar to pan, and bring to a boil. Cook for 1 minute, stirring frequently. Pour applesauce mixture over oat mixture, stirring to coat. Spread mixture in an even layer on a jelly-roll pan coated with cooking spray. Bake at 250° for 1 1/2 hours, stirring every 30 minutes. Allow to cool completely. Stir in chopped apple.
Note: Store granola in an airtight container up to one week.