Preheat your oven to 400°F (200°C).
In a large mixing bowl, combine the ground beef (or turkey), breadcrumbs, egg, onion, garlic, salt, and pepper. Mix until well combined.
Form the mixture into meatballs – about 1 to 1.5 inches in diameter.
Place the meatballs on a baking sheet lined with parchment paper, ensuring they are spaced evenly apart.
Bake in the preheated oven for about 20 minutes or until they are cooked through and have browned slightly.
While the meatballs are baking, warm the buffalo sauce in a saucepan over low heat.
Once the meatballs are done, toss them in the buffalo sauce until fully coated.
Serve hot, drizzled with extra buffalo sauce and garnished with chopped parsley, if desired.