Preheat oven to 350°F. Grease and flour one 10-inch tube pan.
In a large bowl, combine apples, light brown sugar, cinnamon, and nutmeg.
In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.
In a large bowl, combine sugar, eggs, oil, orange juice, orange zest, and vanilla. Slowly add the flour mixture and mix with a spatula until well combined.
Add a small amount of batter to the pan to cover the bottom. Add one quarter of the apple mixture on top. Continue the process layering batter and apples into the pan. Finish the process with batter. As you are layering, the batter does not need to cover the apple layer completely. Sprinkle turbinado sugar on top.
Bake for 1 hour and 20 minutes or until a toothpick inserted in the middle comes out clean. Remove from oven and allow cooling in the pan for 10 minutes. Carefully remove from the pan. Serve warm.