Heat the oven to 400°F. Set an ovenproof rack on a rimmed baking sheet. Spray with nonstick cooking spray and set aside. Place the onions in a ramekin or microwave-safe bowl and microwave on medium power until soft and translucent, about 25 seconds. Set aside to cool slightly. Meanwhile, in a large bowl, combine the turkey, onion, quinoa, parsley, and garlic. Season with salt and pepper. Stir to combine with a rubber spatula. (To taste and adjust for seasoning, simply cook a teaspoon or so of the mixture in the microwave.)

To form the meatballs, using a 1-ounce ice cream scoop or a tablespoon measure, scoop out the meat mixture and roll into a ball about the size of a walnut. Place onto the prepared rack. Repeat until all the meat mixture is used up. Transfer to the oven and cook until firm and the temperature reads 165°F on an instant-read thermometer, about 15 minutes. Remove from the oven and let cool slightly. (These can be made ahead up to this point and stored in an airtight container in the refrigerator for up to 3 days.)

Using a spatula, transfer the meatballs to a medium ovenproof baking dish. Pour over the barbecue sauce and shake the pan a bit to roll and coat the meatballs in the sauce.

Serve immediately or return to the oven and cook until the sauce is bubbly, about 10 minutes. Serve with toothpicks or skewers.