Preheat oven to 375 degrees Fahrenheit. Spray a 9×13-inch baking dish with cooking spray and set aside.

In a bowl, mix together tuna and mayonnaise until creamy. Set aside.

Cook pasta according to package directions. Drain and add tuna, two cups mozzarella, marinara sauce, garlic powder, and onion powder. Mix over medium-low heat until the cheese melts.

Transfer to the prepared baking dish. Top with remaining two cups mozzarella.

Bake 25–30 minutes, until cheese turns golden.