Mix ground chicken, egg, diced onion, garlic powder, salt and pepper into a mixing bowl with your hands until combined. Do not over mix the meat or it will result in very dry meatballs.
Use a scoop or your hands to form 1 inch meatballs. It should make 30+ meatballs. Place the meatballs on a sheet pan that is covered in parchment paper.
Place the sheet pan in the oven and cook for 15-20 minutes or until meatballs are cooked all the way through. They should be 165°F internally when finished.
Remove the meatballs from the sheet pan when finished and place them into a large bowl. Pour the bottle of Buffalo BBQ Sauce into the meatballs and gently mix the meatballs until they are all coated.