Preheat oven to 350℉. Spray 9x13 casserole dish with non stick cooking spray.

Prepare spaghetti to al dente according to the instructions on the package. Don't over cook. Drain and set aside.

While the pasta is cooking, prepare the ultimate cheese layer by mixing all of the ingredients together. Set aside.

In a large skillet on the stovetop over medium heat, begin to brown ground meat. As meat begins to brown, add diced bell pepper, yellow onion and minced garlic. Cook until meat is browned and onions and peppers are cooked through.

Drain away any excess liquid and return meat to the skillet. Stir in diced tomatoes and green chiles and tomato paste. Add in taco seasoning. Mix well. Fold in black beans & corn.

Assemble Mexican Spaghetti Casserole as follows: Layer 1- Spread a thin layer of meat sauce in the bottom of the prepared casserole dish. Layer 2- Add ½ of spaghetti to bottom of dish. Use a fork or tongs to spread over the entire bottom of the dish. Layer 3- Spread all of the cheese mixture over the noodles. Layer 4- Use a fork or tongs to layer the rest of the noodles evenly over the 'ultimate cheese layer,' making sure that the noodles spread all the way out to the edges of the dish. Layer 5- Spread the rest of the meat sauce evenly over the last layer of noodles. Layer 6- Top with 2 cups grated Colby Jack cheese.

Bake in preheated oven for 30 minutes. Garnish with chopped cilantro if desired.