In a large pot, bring salted water to a boil. Add the uncooked ziti pasta and cook according to package instructions until al dente. Drain the pasta in a colander and set aside.
While the pasta is cooking, preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the cooked ziti pasta, basil pesto, peas, and half of the mozzarella cheese. Stir everything together until the pasta is well coated.
Transfer the pasta mixture into a greased 9x13 inch baking dish. Spread it evenly.
Sprinkle the remaining mozzarella cheese over the top of the pasta mixture.
Place the baking dish in the preheated oven and bake for about 25-30 minutes, or until the cheese is melted and bubbly.
Once baked, remove the dish from the oven and let it cool for a few minutes. Serve warm, garnishing with fresh basil if desired.
