Preheat the oven to 375°F. Spray 8 sections of a muffin tin with baking spray, use a pastry brush and brush the baking spray around the cups to make sure they are evenly coated, set aside.
Place the 21 ounce can apple pie filling in a food processor.
Pulse a few times or until roughly chopped, set aside. Note: if you don't have a food processor just take a sharp knife and run it around inside the can to chop up the apples.
Mix together ¼ cup granulated sugar and ¼ cup all-purpose flour in a medium-sized bowl.
Add 2 tablespoons cold unsalted butter, grated or small diced and using your fingers or a pastry cutter, cut in the butter with the flour/sugar mixture until it resembles wet sand with a few larger pieces of butter mixed in no larger than peas, set aside.
Roll out 1 tube crescent roll dough sheet on a clean work surface and cut it into 8 even sections. Gently press the dough into the sections of the muffin tin, making sure to overlap the corners.
Evenly distribute the pie filling among the dough.
Take the corners of the dough and fold them over themselves to form little cups.
Top with the crumble mixture evenly.
Bake for 15 minutes or until golden brown on top. Take them out of the cups and let them cool on a wire rack.
While the cups cool, make the glaze by whisking together 1 cup powdered sugar and 1-2 tablespoons whole milk until smooth. Start with 1 tablespoon of the milk, if the glaze is not pourable, add a little more milk until it is thick yet pourable.
Once the cups are cooled, drizzle with the glaze and serve.
Notes
You can use crescent rolls instead of a dough sheet just make sure you seal the perforations well.
These can be frozen, see my tips above.
You can make your own apple pie filling if you'd like.
You do not need a food processor for this, you can run a knife through the can to chop the apples up or you can dump the filling in the bowl and use a potato masher.
Try sprinkling some ground cinnamon on top of the apple pie filling or adding a little to the glaze!