1-Preheat oven to 350 degrees F (175 degrees C).
2-Mix ground turkey, oats, 1/2 chopped onion, pear applesauce, 3 tablespoons chili powder, egg, garlic, Italian seasoning, salt, and black pepper together in a bowl; press into an 8-inch square baking dish.
3-Heat olive oil in a small saucepan over medium heat; cook and stir 2 tablespoons onion until softened and lightly browned, 5 to 10 minutes. Stir brown sugar, barbecue sauce, and 1 teaspoon chili powder into onion; cook over low heat until sauce is warm, about 5 minutes.
4-Bake meatloaf in the preheated oven, occasionally brushing sauce over the top, until cooked through, about 50 minutes. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).