Preheat your oven to 400 degrees F. Peel and dice the sweet potatoes into 3/4-inch cubes. Chop the onion and bell pepper. Keep the spinach whole or roughly tear any very large leaves.

Toss the diced sweet potatoes with 1 tablespoon of olive oil, paprika, garlic powder, onion powder, salt, and black pepper. Spread in a single layer on a rimmed baking sheet with pieces not touching. Roast for 20 to 25 minutes, flipping once halfway through, until golden at the edges and fork-tender.

While the sweet potatoes roast, heat the remaining 1 tablespoon of olive oil in a large skillet over medium heat. Add the chopped onion and bell pepper and cook for 4 to 5 minutes, stirring occasionally, until softened and slightly translucent.

Add the ground turkey to the skillet. Break it apart with a wooden spoon and cook for 6 to 8 minutes until fully browned with no pink remaining. Season with cumin and an extra pinch of salt and pepper. Remove from heat.

Lightly grease a large baking dish. Layer the roasted sweet potatoes across the bottom. Spoon the cooked turkey mixture evenly over the top, then scatter the fresh spinach across everything. Top with shredded cheddar cheese if using.

Bake at 400 degrees F for 10 to 15 minutes until the cheese is melted and starting to bubble and the spinach has fully wilted. Rest for 2 to 3 minutes before scooping and serving.