This recipe is sponsored by Ninja® Foodi™. All your favorite seasonal flavors come together in this cozy cool-weather dish. A rub made with brown sugar and warm spices is a quick way to add flavor to tender pork. Pop the sweet potato casserole into the oven when the roast is halfway done, and everything will finish together.
a countertop oven, such as a Ninja® Foodi™ XL Pro Air Oven
For the pork: In a small bowl, mix together the brown sugar, pumpkin pie spice, garlic powder, onion powder, mustard powder, 1 tablespoon salt and 1 teaspoon black pepper. Stir in the olive oil to combine. Rub onto the pork on all sides. Put in an 8-by-12-inch rimmed baking dish and let sit at room temperature for 1 hour.
Position the racks in the top and bottom of a large countertop oven and preheat to 350 degrees F.
Transfer the baking dish to the bottom rack of the oven. Cook until the pork is caramel colored and reaches an internal temperature of 145 degrees F, about 60 minutes.
For the sweet potatoes: While the pork roasts, bring a large pot of water to a boil. Melt the butter in a medium saucepan and stir in the brown sugar, 1/2 cup water and a pinch of salt. Bring to a boil, then lower the heat to medium and simmer, stirring, until reduced and thickened, about 10 minutes.
Meanwhile, peel the potatoes and cut them lengthwise, then lengthwise again, making long quarters. Cut the quarters into 1-inch pieces. Boil the potatoes until they give a bit when poked with a fork, about 5 minutes.
Drain the potatoes and arrange in a single layer in a buttered 3-quart baking dish. Pour the syrup on top, making sure it covers the potatoes. Lay the lemon slices on top and bake on the top rack for 35 minutes. The potatoes are done when they are fork tender.
When the pork and sweet potatoes are both done, remove them from the oven and increase the temperature to 400 degrees F. Transfer the pork to a carving board and pour the sauce from the bottom of the pan over it. Let rest while finishing the sweet potatoes, 10 to 15 minutes.
Remove and discard the lemon slices from the sweet potato casserole and stir in the pecans. Top the casserole with the marshmallows and return to the oven on the bottom rack. Cook until the marshmallows puff and turn brown, about 10 more minutes.