In a large mixing bowl, combine the ground beef or turkey, breadcrumbs, Parmesan cheese, green onions, egg, garlic powder, onion powder, salt, and black pepper. Mix until well combined.
Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
Form the meat mixture into 1-inch meatballs and place them on the prepared baking sheet.
Bake the meatballs in the preheated oven for 20-25 minutes, or until they are cooked through and browned.
While the meatballs are baking, prepare the sauce by combining the buffalo sauce, honey, and apple cider vinegar in a small saucepan over medium heat. Stir until well mixed and heated through.
Once the meatballs are done, transfer them to a slow cooker. Pour the honey buffalo sauce over the meatballs and gently stir to coat.
Cover and cook on low for 2-3 hours or on high for 1-2 hours, until heated through and flavors meld.