Sweet Potato Soufflé

A rectangular baking dish filled with sweet potato souffle casserole, topped with pecan crumble and a diagonal line of toasted mini marshmallows. A serving has been scooped out, with a spoon resting in the dish.

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Sweet Potato Soufflé topped with a crunchy pecan-oat streusel and a scattering of marshmallows. This crowd-pleasing sweet potato casserole bakes beautifully in the oven or the air fryer.

Course: Side Dish

Cuisine: American

Keyword: Sweet Potato Soufflé

Servings:

Calories: 603kcal

Author: Lucy Parissi | Supergolden Bakes

Equipment

Ingredients

For the filling

4 large sweet potatoes (approx. 3 lbs / 1.3kg weight)
¾ cup (230ml) maple syrup
½ cup (115g) unsalted butter , melted
1 tsp vanilla extract
½ cup (120ml) whole milk
2 large eggs
1 tsp ground cinnamon , optional
⅓ tsp salt

For the topping

1 cup (115g) chopped pecans or a mix of walnuts, pecans and almonds
½ cup (100g) dark brown sugar
½ cup (65g) quick-cook oats See Note 1
⅓ cup (75g) unsalted butter , melted
¼ tsp sea salt
1 cup (50g) mini marshmallows (optional)

Instructions

Roast the potatoes

In the oven: Preheat to 400°F (200°C). Rinse the sweet potatoes, dry thoroughly, pierce with a fork and place on a rimmed baking sheet lined with parchment paper. Cook for45-60 minutes or until completely soft – a knife should easily pierce all the way through.
4 large sweet potatoes
In the air fryer: Preheat to 375°F (190°C), place the sweet potatoes in the basket with space between them so the air can circulate. Air fry for 30-40 minutes, flipping over halfway, or until soft and caramelized.

Prepare sweet potato filling

Allow the potatoes to cool slightly then peel off the skins. Place the flesh into a large mixing bowl (or the bowl of a stand mixer) and beat until smooth, about 2 minutes.
Beat in the maple syrup, butter and vanilla.
¾ cup (230ml) maple syrup, ½ cup (115g) unsalted butter, 1 tsp vanilla extract
Add the milk, eggs, cinnamon and salt. and beat on low speed until the mash is completely smooth.
½ cup (120ml) whole milk, 2 large eggs, 1 tsp ground cinnamon, ⅓ tsp salt

Make the topping and assemble

Place the chopped nuts, brown sugar, salt and oats in a mixing bowl and stir to combine. Add melted butter and stir together until small and larger clumps form to make the streusel topping.
1 cup (115g) chopped pecans , ½ cup (100g) dark brown sugar, ½ cup (65g) quick-cook oats, ⅓ cup (75g) unsalted butter, ¼ tsp sea salt
Grease a 9x13 baking dish with butter. Transfer the mashed sweet potatoes into the baking dish and level. Sprinkle with the streusel to cover.

Bake the soufflé

In the oven: Preheat the oven to 350°F (180°C). Bake for 35-40 minutes or until the soufflé is set and the topping is a deep golden brown. Scatter with the marshmallows if using and place under the broiler for a couple of minutes until they are lightly toasted.
1 cup (50g) mini marshmallows
In an air fryer: Preheat to 340°F (170°C), place the baking dish in the air fryer basket and cook for 30 minutes. Add the marshmallows if using and increase the heat to maximum. Cook for 2-3 minutes or until the marshmallows are toasted. Cool for 5-10 minutes before serving.

Notes

Note 1: You can use ⅓ cup (45g) all-purpose flour instead of the oats.

Make Ahead: Make the filling and topping up to 2 days ahead and store in separate containers in the fridge. Assemble the casserole and bake.
Storage: The soufflé keeps for 3-4 days in the fridge, covered. Reheat in a 300°F (150°C) oven for 12–18 minutes or in the air fryer at 300°F (150°C) 6–8 minutes.

Nutrition