For the Roasted Sweet Potatoes:

• 3-4 medium sweet potatoes, peeled and cubed
• 2 tablespoons olive oil
• 1 teaspoon ground cinnamon
• 1/4 teaspoon ground nutmeg

For the Casserole Filling:

• Roasted sweet potatoes (from above)
• 1/2 cup milk (or dairy-free milk)
• 1 teaspoon vanilla extract
• 1/4 cup brown sugar
• 2 tablespoons maple syrup
• 1 teaspoon ground cinnamon
• 1/4 teaspoon ground nutmeg
• 1/4 teaspoon ground allspice
• 1/2 cup raisins (optional)
• 1 cup mini marshmallows (plus more for stuffing into the filling)
• 3 tablespoons unsalted butter, cut into small cubes

For the Maple-Pecan Topping:

• 1 cup chopped pecans
• 2 tablespoons maple syrup