Place ½ the diced onion, ground chicken, Parmesan cheese, heavy cream, ½ cup seasoned bread crumbs, 1 tablespoon chopped parsley, egg, chopped capers, garlic powder, salt and pepper in a large mixing bowl.
Use your hands to combine all the meatball ingredients together.
Place ½ cup seasoned breadcrumbs in a shallow dish.
Form chicken into 12 evenly sized meatballs.
Roll meatballs in breadcrumbs to coat them completely.
Heat 2 tablespoons olive oil in a large skillet over medium heat.
Fry meatballs on all sides until browned, about 5-6 minutes.
Remove meatballs from the skillet, and keep them warm.
Add more olive oil to the pan if needed.
Add remaining chopped onion to the skillet and cook until translucent, about 2-3 minutes.
Add 2 tablespoons capers to the pan. Stir to combine.
Add white wine to deglaze the pan, scraping up any browned bits in the bottom of the pan.
Add chicken broth and bring the mixture to a simmer, cooking for 2-3 minutes to reduce the sauce.
Return meatballs to the skillet and cook for 6-8 minutes, spooning the sauce onto the meatballs as they cook.
Add butter cubes and lemon juice to the skillet.
Stir sauce until butter melts and sauce thickens slightly.
Turn off heat and garnish with freshly chopped parsley.
Spoon sauce over cooked pasta and top with meatballs.