Start by preheating your oven to 350°F so it's hot and ready when the spaghetti mixture is done. Boil the spaghetti until just al dente—about 8 to 9 minutes—because it’ll finish cooking in the oven. Be sure not to overcook, or the pasta can become mushy once baked.
While the pasta boils, take this time to cube your Velveeta and shred the chicken if it’s not already done. I usually use rotisserie chicken to save time and give it that extra juicy texture. It also saves one more step during prep, which is a bonus when you’re in a hurry.
Once the pasta is cooked and drained, place it in a large mixing bowl. Add the shredded chicken right in with it. Then pour in the cream of mushroom soup, cream of chicken soup, and the entire can of Rotel (don’t drain it—those juices help build flavor). Sprinkle in the seasoned salt and black pepper.
Toss the Velveeta cubes into the same bowl. At this point, I like to pop the entire bowl into the microwave for a minute or two, just to help start melting the cheese and make it easier to stir. Stir until everything is evenly combined and the cheese begins to coat the pasta in a creamy layer.
The mix will look thick and rich—and that’s exactly what you want. Don’t worry if the cheese isn’t completely melted yet. It’ll finish melting in the oven and create that irresistible creamy texture.
Transfer the entire mixture into a greased 9×13-inch baking dish. Spread it out evenly with a spatula, making sure every corner gets filled. If you like a golden top, you can sprinkle a little shredded cheddar on top, but it’s optional.
Bake uncovered for about 40 to 45 minutes, or until the edges are bubbling and the cheese is fully melted. If the top is browning too fast but the inside still needs time, loosely cover with foil during the last 10 minutes.
Once it’s out of the oven, let it sit for about 5 minutes before serving. This helps the sauce thicken a bit and makes it easier to serve in neat squares or scoops. It’s cheesy, creamy, and absolutely satisfying—the kind of dish that leaves everyone asking for seconds.