Preheat the oven to 375°F (190°C) and line a baking sheet with parchment paper.
In a bowl, combine ground chicken, ricotta, Parmesan, breadcrumbs, garlic, Italian seasoning, parsley, egg, salt, and pepper. Mix gently until just combined.
Shape into 12-16 equal-sized meatballs and place on the baking sheet.
Bake for 20-25 minutes, until golden brown and the internal temperature reaches 165°F (74°C).
In a skillet, melt butter over medium heat. Add spinach and sauté until wilted. Set aside.
In the same skillet, melt more butter and sauté garlic for 1 minute. Add heavy cream and bring to a gentle simmer. Stir in Parmesan cheese, nutmeg, salt, and pepper; cook until the sauce thickens (3-5 minutes).
Add wilted spinach to the sauce and stir to combine.
Gently place baked meatballs into the sauce; allow them to simmer briefly so they can soak up some flavor.
Serve hot over pasta, zucchini noodles, or on its own with a side of crusty bread.