Sweet Potato Base

1. Preheat oven to 350F.
2. Peel and chop sweet potatoes into 1 1/2" chunks. Transfer to a large saucepan and cover with water (add about 1" of extra water.) Bring to a boil over high heat and cook until potatoes are fork tender. While potatoes are boiling, begin whipping aquafaba marshmallow topping (below.)
3. Drain potatoes and mash with butter, brown sugar, almond milk, vanilla, cinnamon, ground ginger, pumpkin pie spice (optional), and a pinch of salt. Mix well and taste. Adjust salt to suit your preference.
4. Layer the sweet potatoes into the bottom of a 5" x 7" casserole dish. Top with aquafaba mixture (directions below), and bake for 15-20 minutes. Finish under the broiler if the topping isn't toasty enough.

Aquafaba Marshmallow Topping

1. A stand mixer with a wire whisk attachment works best for making this aquafaba topping. A hand mixer is a good substitute but it will take longer to reach soft and firm peaks.
2. Combine the chickpea liquid and cream of tartar. Beat on high until soft peaks form. Depending on the quality of your chickpea liquid this can take just a few minutes up to 10 minutes.
3. Slowly add the sugar and continue beating until stiff peaks form. Rub a small amount of the meringue between your fingers, if the mixture feels gritty continue beating until the sugar dissolves.
4. Tip: You can’t overbeat aquafaba the same way you can overbeat egg whites. If in doubt, beat the aquafaba a little longer.