Combine the peeled and chopped apples with the cinnamon, brown sugar, vanilla and corn starch.
Use the pot in pot method to pressure cook the apples for 4 minutes. I like my apples with a little bite, not too mushy. If you prefer yours to be softer, I'd recommend pressure cooking for a minute or two longer. **See notes for more details about pot in pot.**
While the apples are in the Instant Pot, use a fork and cut the ingredients for the crumb topping together.
Quick release the pressure when the time has expired. Transfer to a larger dish, if desired. Top with the crumb topping.
Broil on the middle rack for 5-10 minutes, or until the topping is golden brown.
Serve with ice cream, whipped cream, or some vanilla icing.