Scrub the sweet potatoes thoroughly. For the Instant Pot, place on a trivet, add 1 cup of water, secure the lid, and set for 15 minutes at high pressure. Allow a natural release for 10 minutes. For the oven, preheat to 425°F, poke holes in the potatoes, and bake for 45-50 minutes until tender. Let cool.

Peel the cooled sweet potatoes and transfer to a large mixing bowl. Mash them using a hand mixer until smooth and creamy. Gradually mix in dairy-free butter, brown sugar, cinnamon, gluten-free flour, vanilla extract, and any additional sweeteners.

In a separate bowl, combine chopped pecans with dairy-free butter, brown sugar, and cinnamon. Mix until pecans are coated and set aside to meld flavors.

Grease a 9x13 inch baking dish with dairy-free butter. Spread sweet potato filling evenly in the dish and sprinkle pecan topping over it.

Preheat oven to 350°F. Bake the casserole for 35-40 minutes, or until golden brown and bubbling. For extra crispiness, broil for 2-3 minutes, watching closely to prevent burning.