Preheat your oven: Begin by preheating your oven to 350°F (175°C). This step is crucial for ensuring that your casserole cooks evenly.
Prepare the baking dish: Spray a 9x13-inch baking dish with nonstick spray to prevent sticking. This will make serving the casserole much easier.
Mix the creamy mixture: In a large mixing bowl, combine 10.5 oz of cream of chicken soup, 1.5 cups of sour cream, and the 1 oz ranch seasoning packet. Stir in 1/2 cup of grated cheddar cheese until all ingredients are well incorporated.
Layer the chicken: Spread 2 lbs of chicken tenderloins evenly across the bottom of the prepared baking dish. Ensure that the chicken pieces are uniformly distributed for even cooking.
Add the creamy mixture: Pour the creamy mixture over the chicken, ensuring that all pieces are covered. This mixture will help cook the chicken while adding flavor.
Top with crackers: Evenly sprinkle 40 crushed Ritz crackers over the top of the casserole. This will create a deliciously crunchy topping when baked.
Bake: Place the baking dish in the preheated oven and bake for 25-30 minutes or until the chicken is cooked through and the top is golden brown. You can check for doneness by ensuring that the internal temperature of the chicken reaches 165°F (74°C).
Serve: Once baked, remove the casserole from the oven and let it sit for a few minutes to cool before serving. Enjoy it on its own or pair it with a side of rice or a fresh salad!