Pat chicken thighs dry and season both sides with salt. Heat a large skillet over high heat and sear the thighs for 2 to 3 minutes per side until golden brown. Set aside.

In the Crock Pot, combine heavy cream, chicken broth, shredded Parmesan, ranch dressing mix, minced garlic, salt, and pepper. Stir thoroughly until the sauce is smooth.

Place the seared chicken thighs on top of the sauce in the Crock Pot. Sprinkle extra grated Parmesan, salt, and pepper over the top. Cover and cook on high for 1 to 2 hours or on low for 2 to 3 hours, until the chicken reaches an internal temperature of 165 degrees F. Stir and scrape the bottom of the insert with a plastic spatula every 30 minutes to prevent burning.

Once the chicken is cooked through, sprinkle fresh chopped basil over the top and squeeze the juice of half a lemon over everything. Taste and adjust seasoning as needed.

Cook spaghetti or your pasta of choice according to package directions in a large pot of salted boiling water. Before draining, reserve 1 cup of pasta water.

Remove chicken thighs from the Crock Pot and set aside. Add the drained pasta directly to the sauce in the Crock Pot and toss well to coat. Add reserved pasta water a splash at a time if the sauce is too thick.

Divide the sauced pasta among individual bowls and place a chicken thigh on top of each serving. Finish with extra grated Parmesan and fresh basil. Serve immediately.