Preheat your oven to 375°F (190°C) and lightly grease a 9x9 baking dish with olive oil or nonstick spray.

Melt 2 tablespoons of unsalted butter in a medium saucepan over medium heat. Add 2 minced garlic cloves and stir for about 1 minute until fragrant. Gradually whisk in 1 cup of heavy cream and cook over medium-low heat for 5-7 minutes until the sauce thickens. Stir in 1 cup of grated Parmesan cheese, seasoning with salt and pepper to taste, then set aside.

In a skillet over medium heat, add 6 slices of diced bacon. Cook for approximately 5-7 minutes until crispy, then transfer to a paper towel-lined plate, leaving about 1 tablespoon of bacon grease in the skillet.

In the same skillet with the reserved bacon grease, add 1 pound of diced chicken thighs. Toss with 1 tablespoon of olive oil and 2 tablespoons of ranch seasoning. Sauté for 8-10 minutes until cooked through and golden brown, then set aside.

Bring a large pot of salted water to a boil. Add 8 ounces of rotini pasta and cook according to the package instructions until al dente, then drain and return to the pot.

Add the cooked pasta, alfredo sauce, sautéed chicken, and crispy bacon to the baking dish. Gently mix until well combined.

Sprinkle 1 cup of shredded mozzarella cheese and 1/2 cup of shredded cheddar cheese on top of the casserole.

Bake in the preheated oven for 15-20 minutes or until the cheese is bubbly and golden.

Let the casserole cool for a few minutes, then garnish with freshly chopped parsley before serving.