In a large pot over medium heat, add diced bacon and cook for 5-7 minutes until crispy and golden brown. Stir frequently to ensure even cooking. Once done, use a slotted spoon to remove the bacon, letting it drain on a paper towel, while leaving the flavorful drippings in the pot for the next steps.

Add diced onion to the pot with the remaining bacon drippings, and sauté for about 5 minutes or until the onion is translucent and fragrant. Next, stir in minced garlic and chopped rosemary, cooking for another minute until aromatic but not browned.

Incorporate diced boneless, skinless chicken breasts into the pot, seasoning generously with salt and pepper. Cook for 5-7 minutes, stirring occasionally, until the chicken is lightly browned and cooked through.

Pour in the chicken broth and bring the mixture to a simmer. Allow it to cook for 2 minutes.

Gently stir the pierogi into the bubbling broth. Cover the pot and cook according to the package directions, typically about 5-7 minutes.

Slowly pour in the heavy cream, stirring continuously. Allow the soup to simmer gently for another 5 minutes.

Ladle the Creamy Pierogi Chicken Soup into bowls, topping each serving with the reserved crispy bacon bits. Optionally garnish with chopped parsley.