- 2 cups mashed sweet potatoes
- 1/4 cup milk
- 2 tablespoons butter, softened
- 1/2 teaspoon ground cinnamon
- salt and ground black pepper to taste
- 1 egg, separated
- 1 (10.5 ounce) package miniature marshmallows
- Preheat oven to 350 degrees F (175 degrees C).
- Mix sweet potatoes, milk, butter, cinnamon, salt, and pepper together in a bowl.
- Beat egg yolk in a bowl until smooth; mix into sweet potato mixture. Beat egg white in a separate bowl until frothy; fold into sweet potato mixture. Transfer sweet potato mixture to a 9-inch square baking dish; top with marshmallows.
- Bake in the preheated oven until heated through and marshmallows are golden brown, 20 to 30 minutes.