Add finely crushed cheerios to a bowl and add rest of crust ingredients. Stir together until combined. Press firmly into the bottom and about 1/2 inch up the sides of a 6 inch push pan. Freeze until filling is ready.
To make filling, you can whisk by hand or with a food processor. Add cream cheese and brown sugar to a bowl. Whisk until smooth and combined. Add pumpkin puree, tapioca starch, and salt, and stir until just combined and no streaks of pumpkin remain. Add eggs, vanilla, cinnamon, and cardamom, and stir until just combined.
Take pan out of freezer and pour filling in. Tap on counter firmly to move any air bubbles out. Set in OXO sling.
Pour 1 cup water into your Instant Pot and add trivet. Then set pan via sling onto the trivet. Fasten the sling and close lid. Set to manual, high pressure. Cook for 35 minutes. Let Instant Pot naturally release, which will take about 20 minutes. Take lid off as soon as it is naturally released.
Remove cheesecake from Instant Pot and let cool. Cover and refrigerate until ready to serve.
Top with homemade whipped cream and serve.