Save space on your stove top this Thanksgiving by using your Instant Pot for most of the prep work for this Instant Pot Sweet Potato Casserole!
Place the sweet potatoes and water in the Instant Pot. Close the lid and lock, be sure the pressure valve is shut. Press "Manual" for 8 minutes. Use quick release for the pressure.
Drain the sweet potatoes and return to the Instant Pot (make sure it's off). Stir in the eggs, butter, sugar, milk and vanilla until smooth.
Preheat the oven at 350 degrees. Grease a 8x8 round glass baking dish. Add the sweet potato mixture to the dish and spread evenly.
In a small glass bowl, add the walnuts, brown sugar, flour and butter. Stir to combine. Crumble over the sweet potatoes.
Top with marshmallows. Bake for 30 minutes.