Preheat the oven to 375°F (190°C). Lightly coat a baking dish with cooking spray or a small amount of olive oil.

Bring a large pot of water to a boil. Carefully add the sweet potato slices and parboil for about 8 minutes, or until slightly tender while still firm enough to hold their shape. Drain well and set aside.

Heat a little of the olive oil in a large skillet over medium heat. Add the spicy beef sausage, breaking it into crumbles with a wooden spoon. Cook for about 8 minutes, or until browned and completely cooked through. Remove from the heat.

Place the sliced apples in a bowl. Toss them with 1 teaspoon cinnamon, salt, black pepper, and a small drizzle of olive oil until evenly coated.

Arrange half of the sweet potatoes across the bottom of the prepared baking dish. Add half of the cooked beef sausage, followed by half of the seasoned apples and some of the chopped pecans.

Repeat the layers with the remaining sweet potatoes, sausage, and apples. Sprinkle the remaining cinnamon over the casserole.

Finish the Sweet Potato and Sausage Casserole with an even layer of shredded cheddar cheese and the remaining chopped pecans. Cover loosely with foil.

Bake for approximately 30–35 minutes. Remove the foil during the final 5 minutes so the cheese can become bubbly and lightly golden.

Remove the casserole from the oven and let it rest for about 5 minutes before serving.