Preheat your oven to broil.
In a large pot, cook the penne pasta to box directions. Strain.
Pour the strained pasta back into the pot. Stir in the asparagus tips, pesto & ranch. Taste - add more of either if you'd like to. Stir in 1/2 cup of mozzarella cheese.
Spray a medium casserole dish with non-stick cooking spray. Scoop in the pasta. Top with remaining cheese. Broil for 2-4 minutes, or until the cheese is melted & starting to brown.