Meanwhile, make the filling: Heat the 2 teaspoons olive oil in a large, deep saucepan over medium heat. Add the ground turkey, all of the white parts and half of the green parts of the green onion, bell pepper, chili powder, garlic powder, smoked paprika, cumin, salt, and black pepper. Cook, breaking up the meat, until it is no longer pink and the vegetables are tender, about 5 minutes. Stir in the black beans and fire-roasted tomatoes. Increase the heat to high and cook until the mixture is thickened and most of the tomato juice has cooked off, about 5 minutes. Taste and adjust seasoning as desired. Stir in 1/2 cup of the shredded cheese.

Once the squash is cool enough to handle, use a fork to shred and fluff the inside flesh so it’s no longer attached to the walls and makes a “nest.” Divide the taco filling evenly among the boats, using a fork to lightly mix it with the spaghetti squash. Arrange the stuffed squash on baking sheets and sprinkle with the remaining cheese.

Bake until the cheesy is bubbly, about 10 minutes. Let cool for a few minutes, then serve hot, sprinkled with any desired toppings.