Preheat the oven to 400°F and line a baking sheet with parchment paper.
Carefully cut each zucchini in half lengthwise and trim off the ends. Then, use a spoon to scoop the inside out, leaving at least a 1/4-inch thick rim. It will look like a boat.
Place the zucchini boats face-side up, spray with nonstick spray or drizzle some olive oil on top, season with salt and pepper.
Bake for 10 - 12 minutes, until fork-tender.
Meanwhile, heat a large non-stick pan with 1 Tablespoon of olive oil to medium. Add in the red onion and bell pepper. Stir and let simmer for 3 minutes.
Create space in the middle of the pan by pushing onions and bell peppers to the side and add in the ground turkey. Cook for another 3 - 4 minutes, breaking up the meat with your spatula as it cooks.
Add in cumin, chili powder, paprika, and minced garlic. Stir to fully combine.
Add in the tomatoes, cooked quinoa, corn, cilantro, and lime juice. Stir and let cook for 1 - 2 minutes. Taste, adjust seasonings, and season with salt and pepper to taste.
Remove zucchini boats from the oven and evenly spoon turkey quinoa mixture into each boat. Top with cheddar cheese and bake for another 10 - 12 minutes until the filling is warm and the cheese is bubbly.
Garnish with fresh cilantro and serve with salsa, guacamole, or sour cream.