- In a large bowl, toss together peaches, blackberries, lemon juice, sugar, cornstarch, vanilla, cinnamon, and a pinch of salt. Pour mixture into an Instant Pot.
- In a new bowl combine ingredients for crumble: sugar, flour, oats, cinnamon, salt and shredded butter. Crumble together with your hands of pastry blender until mixture is sandy and crumbles are about a nickel size. Top evenly on top of fruit mixture.
- Place ramekins on top of grate with one cup of water in the instant pot or the mixture directly onto the bottom of the instant pot. Seal the lid on and place the pressure valve to seal. Cook on manual high pressure for 17 minutes.
- Quick release the pressure and allow crisp to cool for five minutes. Top with vanilla ice cream just before serving.
*Note: you can replace the peaches and blackberries with 5-6 cups of your desired fruit.