This make-ahead sweet potato casserole is an easy side dish you could make in advance.
This make-ahead sweet potato casserole is theperfect solutionfor busy holiday weeks.
Bring to room temperature, then warm at 325F until hot throughout before serving.

Credit: Greg Dupree; Food Stylist: Emily Neighbors Hall; Prop Stylist: Audrey Davis
Place sweet potatoes and water in a large saucepan; bring to a boil over high.
Cover and reduce heat to medium-low; simmer until sweet potatoes are very tender, about 25 minutes.
Return sweet potatoes to pan; mash using a masher to desired consistency.
Whisk in 2 cups of the mashed sweet potatoes 1/2 cup at a time.
Add mixture to remaining mashed sweet potatoes in pan; stir until well combined.
Add 1/2 cup of the butter, stirring until melted.
Add remaining 1 cup butter; work butter into oat mixture using your fingers until well combined.
Sprinkle evenly over casserole in baking dish.
(If making ahead of time, cover casserole, and store in refrigerator up to 4 days.)
Bake casserole:
Bake in preheated oven until top is browned, 50 to 55 minutes.
Let stand at room temperature 10 minutes.
confirm to drain your boiled sweet potatoes thoroughly to avoid excess liquid that could cause a watery filling.
Swap the all-purpose flour with a gluten-free flour blend or oat flour for a gluten-free version of this casserole.