Preheat oven to 400 degrees F. Line a baking sheet with parchment paper.
In a large bowl, combine ground chicken, egg, onion powder, garlic powder, salt, pepper, parsley, breadcrumbs, Parmesan cheese, Worcestershire sauce and milk. Mix just until combined, don't over-mix.
Portion into meatballs (I got about 22-24 meatballs). I find just using your hands works best. You can dampen your hands to make meatballs easier to roll.
Stuff a few crumbles of Treasure Cave Mild Blue Cheese into middle of each meatball. Pinch some of the meatball around the cheese to cover it up and reroll them.
Transfer meatballs to pan and bake for 18-20 minutes or until they reach an internal temperature of 165 degrees F.
While meatballs are cooking, prepare sauce. Add buffalo sauce to a medium saucepan and bring to a light simmer.
Remove from heat and add cold butter, whisking until melted.
When meatballs are done cooking, toss them in buffalo sauce.
Serve with chopped celery and more Treasure Cave Crumbled Mild Blue Cheese for garnish.