Set up your instant pot with 1 cup of water in the bottom along with the wire rack. Set an oven safe dish inside, I used a 4 cup Pyrex dish.
Place your washed, peeled cored and cut applies into the dish and sprinkle with the cinnamon. Twist on the locking lid, set to Manual or Pressure Cook for 6 minutes.
While the apples cook, preheat the oven to 375°F
Use a pastry cutter or fork to mix together the flour, sugar, oats and flax until you have a crumble that will hold together when you squeeze it. You can opt to use a little more or less sugar and butter to your preference.
Bake for about 15 minutes or until golden brown and the granola like crumble topping stays together in clumps.
When the time is up on the Instant Pot, carefully do a quick release for the pressure and check your apples. Ours were super soft on top and then a little more crisp down towards the bottom. This was a really nice blend when mixed together.
Top the apples with the finished crumble and enjoy!