Bring the quinoa and water or chicken stock to a boil in a saucepan over high heat. Reduce heat to medium-low, cover, and simmer until the quinoa is tender, and the water has been absorbed, about 15 to 20 minutes. Set aside to cool.
Heat an oven to 350° F.
Heat the olive oil in a skillet over medium heat. Stir in the onion, carrot and bell pepper, sauté until the onion has softened and turned translucent, about 5 minutes. Add the garlic and cook for another minute; remove from heat to cool.
In a large bowl, stir the turkey, cooked quinoa, cooked veggies, tomato paste, cayenne, onion and garlic powder, 2 tablespoons Worcestershire, eggs, salt, and pepper until well combined. The mixture will be very moist. Shape into a loaf on a parchment or foil lined rimmed baking sheet.
Combine the brown sugar and 2 teaspoons Worcestershire in a small bowl. Rub the paste over the top of the meatloaf.
Bake in the preheated oven until no longer pink in the center, about 50 minutes. An instant-read thermometer inserted into the center should read at least 160° F. Let the meatloaf cool for 10 minutes before slicing and serving.