Preheat your oven to 375°F (190°C). Lightly coat a 12-cup muffin tin with cooking spray or a little oil.
Combine the ground chicken, diced onion, 10 cloves of minced garlic, breadcrumbs, egg, 3 tablespoons of parsley, 3 ounces of Parmesan cheese, 1 teaspoon of salt and the black pepper in a large bowl. Mix gently until the ingredients are distributed evenly.
Divide the chicken mixture into 12 equal portions. Shape each portion into a ball and press it lightly into a muffin cup.
Bake the meatloaves for 22 to 25 minutes. Check that the internal temperature reaches 165°F (74°C) using a meat thermometer.
Let the mini meatloaves rest in the pan for 5 minutes after removing them from the oven.
Heat the olive oil in a small saucepan over medium heat while the meatloaves rest. Add the remaining 3 cloves of minced garlic and cook for 1 to 2 minutes until fragrant.
Stir in the flour and cook for 1 minute. Slowly pour in the heavy cream while whisking constantly to prevent lumps. Cook for 3 to 4 minutes until the sauce thickens slightly.
Remove the saucepan from the heat. Stir in the remaining 3 ounces of Parmesan cheese, 1/4 teaspoon of salt and 1 tablespoon of parsley until the cheese melts into a smooth sauce.
Transfer the meatloaves to plates and spoon the warm garlic cream sauce over them before serving.