Cook the spaghetti in salted water according to the package instructions until al dente. Drain and set aside.
In a large, deep skillet, heat olive oil over medium heat. Add the onions and cook until tender. Then, add the garlic and cook until fragrant.
Add the ground beef to the skillet, and using your spatula break it into small pieces. Season the beef with salt, ground pepper, and garlic powder. Cook the beef until fully browned, then drain any excess fat.
Stir in the Rotel, taco sauce, and cooked spaghetti, tossing everything together to coat the pasta evenly. Reduce the heat to medium-low to keep everything warm.
Mix the taco seasonings together and sprinkle them over the pasta. Toss to coat, then stir in 1 cup of cheese. Taste and adjust the seasonings as needed, adding more cheese if desired.
Top the pasta with the remaining cheese, then cover the skillet with a lid to allow the cheese to melt.
Finish by sprinkling fresh cilantro and chopped green onions over the top. Serve the taco spaghetti with your favorite taco toppings.
Enjoy!