Ingredients:

  • 4 lbs sweet potatoes (Garnet or Jewel), peeled and cut into 2-inch chunks
  • 1/2 cup unsalted butter, melted
  • 1/2 cup light brown sugar, packed (for filling)
  • 2 large eggs, lightly beaten
  • 1/4 cup whole milk or half-and-half, room temperature
  • 1 tsp pure vanilla extract
  • 1 tsp ground cinnamon (for filling)
  • 1/2 tsp freshly grated nutmeg
  • 1/2 tsp fine sea salt (for filling)
  • 1 tsp orange zest (optional)
  • 3/4 cup all-purpose flour
  • 1/2 cup light brown sugar, packed (for topping)
  • 1/2 cup unsalted butter, cold and cubed (for topping)
  • 1 cup pecan halves or chopped pecans, lightly toasted
  • 1/4 tsp ground cinnamon (for topping)
  • Pinch of salt (for topping)

Instructions:

  1. Prep and Cook Potatoes: Peel the sweet potatoes and cut them into uniform 2-inch (5 cm) chunks. Place them in a large pot and cover with cold, salted water. Bring to a boil, then reduce heat and simmer for 15–20 minutes until easily pierced with a fork.
  2. Drain and Dry: Drain the potatoes thoroughly using a colander. Return the drained potatoes to the empty hot pot over low heat for 1–2 minutes, shaking the pot, to evaporate excess moisture. Transfer to a bowl and allow them to cool for 15 minutes.
  3. Mash and Mix Wet Ingredients: Using a potato masher, mash the sweet potatoes until mostly smooth. In a separate small bowl, whisk together the melted butter, brown sugar (filling portion), eggs, milk, vanilla, and orange zest.
  4. Create the Filling: Pour the wet mixture over the mashed potatoes. Add the cinnamon (filling portion), nutmeg, and salt. Fold gently until just combined and creamy. Lightly grease a 9x13 inch baking dish and spread the mixture evenly.
  5. Chill (Make-Ahead Step): Cover the casserole dish tightly and refrigerate for at least 4 hours, or preferably overnight (up to 48 hours).
  6. Preheat and Prepare Topping: Preheat your oven to 350°F (175°C). While the oven heats, allow the casserole to sit at room temperature for 15 minutes. In a medium bowl, combine the flour, brown sugar (topping portion), cinnamon (topping portion), and salt. Add the cold, cubed butter.
  7. Form Streusel: Use a pastry blender or your fingertips to cut the butter into the dry ingredients until coarse crumbs form. Stir in the toasted pecans.
  8. Bake: Sprinkle the streusel topping evenly over the sweet potato filling. Bake for 40–50 minutes, or until the topping is golden brown and bubbling slightly around the edges and the center is set. Allow the casserole to rest for 10–15 minutes before serving.