Preheat oven to 375℉ Grease the inside of an 8x8-inch casserole dish with nonstick cooking spray.
Place the drained sweet potatoes into a large mixing bowl. Use a potato masher or a hand mixer to mash them until smooth.
Add brown sugar, maple syrup, melted butter, salt, cinnamon, nutmeg, and vanilla extract to the bowl. Stir until fully incorporated.
Spread the mashed sweet potato mixture evenly into the prepared baking dish.
Sprinkle the top of the casserole with chopped pecans, then evenly distribute mini marshmallows.
Bake for 20-25 minutes or until the marshmallow topping is golden brown.
Remove the casserole from the oven and let cool slightly. Serve warm and enjoy!
Notes
Storage and Freezing
Storage: Store leftover sweet potato casserole in an airtight container in the refrigerator for 1-2 days. Cover the cooled casserole with plastic wrap or aluminum foil if keeping it in the original dish.
Freezing: For longer storage, transfer the whole casserole or individual portions into a freezer-safe container. Freeze for up to three months. Thaw overnight in the fridge before reheating.
Reheating: Warm the casserole in a preheated oven at 350 degrees until heated through.
Natalie’s Pro Tip
If you want fresh sweet potatoes for the casserole, I recommend baking them instead of boiling them. Boiling can make the sweet potatoes watery and lead to a runny casserole.To prevent the marshmallow topping from burning, when the marshmallows have browned, you can loosely cover the casserole with a piece of foil