In a medium bowl, combine oats, flour, brown sugar, cinnamon, and salt.
Cut in the cold butter with a fork or pastry cutter until mixture resembles coarse crumbs.
Sprinkle evenly over the apple layer.
Step 5: Bake the Cheesecake
Place the springform pan on a baking sheet to catch drips.
Bake at 325°F (163°C) for 55–65 minutes, or until edges are set but the center still jiggles slightly.
Turn off oven, crack the door, and let cheesecake cool for 1 hour inside.
Remove and refrigerate at least 6 hours or overnight.
