Sweet Potato Caserole Recipe

Prepare and cook sweet potatoes

Preheat oven to 375°F (190°C). Place peeled, cubed sweet potatoes in a large pot and cover with cold water by about 1 inch. Add a pinch of salt. Bring to a boil over high heat, then reduce to a simmer and cook until very tender, about 15-20 minutes depending on cube size. Drain thoroughly.

Mash and combine

Return drained potatoes to the warm pot (off heat) or a large bowl. Add 4 tablespoons unsalted butter and mash until smooth (use a potato masher or hand mixer for a silkier texture). Stir in 1 cup brown sugar, 1 teaspoon vanilla extract, 1 teaspoon ground cinnamon, 1/4 teaspoon ground nutmeg, and 1/2 teaspoon kosher salt until evenly incorporated.

Finish custard-like base

Whisk together 2 large eggs and 1/4 cup milk in a small bowl. Temper the eggs by adding 1-2 tablespoons of the warm mashed sweet potato mixture into the egg mixture while whisking, then fold the egg mixture back into the sweet potatoes. Mix until smooth and homogenous. Taste and adjust seasoning—if you prefer sweeter, add up to 2 tablespoons more brown sugar. The mixture should be spreadable but hold shape.

Assemble in baking dish

Lightly butter a 9x9-inch (or similar 8x8 to 9x13 depending on desired thickness) baking dish. Spread the sweet potato mixture evenly into the dish and smooth the top with a spatula or back of a spoon.

Make streusel

In a medium bowl, combine 1/2 cup all-purpose flour, 1/2 cup packed brown sugar, 1/4 teaspoon ground cinnamon, and 1/8 teaspoon fine salt. Add the 4 tablespoons cold cubed butter. Using a pastry cutter, two forks, or clean fingertips, cut the butter into the dry ingredients until the mixture forms coarse crumbs with some pea-sized pieces of butter remaining.

Add pecans

Fold 3/4 cup chopped pecans into the streusel mixture until evenly distributed.

Top the casserole

Evenly sprinkle the pecan streusel over the sweet potato layer, pressing lightly so it adheres in spots but remains crumbly on top.

Bake

Place the assembled casserole in the preheated 375°F (190°C) oven and bake until the topping is golden and the filling is heated through, about 25-30 minutes. If you are using a larger, shallower dish (9x13), check after 20 minutes; for deeper 8x8, it may take closer to 30 minutes.

Optional marshmallow finish

If using mini marshmallows, remove the dish from the oven about 5 minutes before the end of baking. Sprinkle 1 cup mini marshmallows evenly over the top and return to the oven for 3-5 minutes until marshmallows are puffed and lightly browned. Optionally brush marshmallows very lightly with 1 tablespoon melted butter for sheen.

Rest and serve

Remove the casserole from the oven and let rest for 10 minutes to set. Serve warm as a side dish. Leftovers can be cooled completely, covered, and refrigerated for up to 3 days. Reheat in a 350°F (175°C) oven until warmed through.