Preheat oven to 350 degrees Fahrenheit. Line a small sheet pan with parchment paper.
Use a large spoon to scoop the top off each apple. Make a large circle around the stem and scoop it off.
Now use a smaller spoon to scoop out the seeds and core, like scooping out the inside of a pumpkin.
Throw the seeds and core away. Place the cored apples on the prepared sheet pan. Brush each apple with melted coconut oil.
In a medium bowl, combine the almond flour, brown sugar, cinnamon, quick-cooking oats, and chopped pecans. Stir to combine.
Add the maple syrup and coconut oil. Use a large spoon or your hands to mix well until a crumble forms.
Divide the crumble between the apples, using clean hands to push the crumble down into the middle of each apple.
Remove any excess crumble from the sheet pan.
Bake the apples on the middle rack until soft, about 35 to 40 minutes. If the topping gets too brown, you can loosely cover it with foil.
Carefully remove the apples from the oven and enjoy warm!