Ingredients:
Sweet Potato Filling:
- 5 lbs sweet potatoes (about 6 medium-sized)
- ½ cup (1 stick) unsalted butter, softened
- 2 large eggs, lightly beaten
- 1 teaspoon ground cinnamon
- ½ teaspoon ground nutmeg
- 1 teaspoon vanilla extract
- ¾ cup dark brown sugar
- ¼ cup heavy cream
- 1 teaspoon salt
Streusel Topping:
- 1 cup all-purpose flour
- 1 cup packed brown sugar
- ½ cup rolled oats
- ½ teaspoon ground cinnamon
- ½ cup (1 stick) unsalted butter, cold and cut into cubes
- 1 cup chopped pecans (optional)
Instructions
Prep the Sweet Potatoes:
- Preheat the oven to 350°F (175°C).
- Wash and scrub the sweet potatoes. Pierce each potato several times with a fork.
You can either:
- Bake: Wrap potatoes in foil and bake for 1 hour, or until tender when pierced with a knife.
- Boil: Peel, cube, and boil potatoes until fork-tender (about 15 minutes). Drain thoroughly.
Make the Filling:
- If baked: Allow potatoes to cool slightly. Peel and place the flesh in a large bowl.
- If boiled: Place drained, cooked potatoes in a large bowl.
- Mash sweet potatoes with softened butter until mostly smooth (a few lumps are okay).
- Beat in the eggs, cinnamon, nutmeg, vanilla extract, brown sugar, heavy cream, and salt until combined.
Prepare the Streusel:
- Combine flour, brown sugar, oats, and cinnamon in a medium bowl.
- Use a pastry cutter or your fingers to cut in the cold butter until the mixture resembles coarse crumbs.
- Stir in the chopped pecans (if using).
Assemble:
- Spread the sweet potato mixture evenly in a greased 9×13 inch baking dish.
- Sprinkle the streusel topping generously over the sweet potato layer.
Bake:
- Bake for 30-35 minutes or until the topping is golden brown and the filling is heated through.
Optional Marshmallow Topping:
- For the classic Boston Market experience, top with mini marshmallows during the last 5 minutes of baking.
Tips:
- Sweet Potato Variety: Garnet or Jewel sweet potatoes are classic choices for their sweetness and vibrant color.
- Smoothness: Adjust how much you mash the sweet potatoes for your desired texture.
- Make-Ahead: Prepare the casserole (without topping) a day ahead. Store covered in the refrigerator. Add the topping and bake just before serving.
- Customize It: Add a hint of ginger or other spices to the filling or topping.
