Boil water in your large pot. Add a pinch of salt to water.
Cook spaghetti according to package directions. Drain pasta and set it aside. Don't overcook the noodles at all.
Mix soups in a large bowl. Add diced tomatoes with their juice.
Pour in the chicken broth slowly. Stir in onion, bell pepper, and garlic.
Add shredded chicken to the mixture. Season with salt, pepper, and chili powder.
Add cooked spaghetti to chicken mixture. Stir gently until everything is coated.
Make sure pasta is evenly distributed. The mixture should look creamy and combined.
Preheat your oven to 350°F. Grease your 9x13 inch baking dish.
Pour half the spaghetti mixture into dish. Sprinkle 1 cup cheese over the layer.
Add remaining spaghetti mixture on top. Top with remaining cheese evenly.
Cover dish with aluminum foil loosely. Bake for 30 minutes covered first.
Remove foil and bake 15 more minutes. Cheese should be bubbly and golden.
Let it cool for 5 minutes. Serve hot and enjoy the deliciousness.