Begin by bringing a large pot of salted water to a boil over high heat. Add the rotini pasta and cook according to the package instructions, typically 10-11 minutes, until al dente. Once cooked, drain the pasta in a colander and rinse thoroughly with cold water to stop the cooking process and cool it down.

In a large mixing bowl, combine the prepared Italian dressing, freshly squeezed lemon juice, grated Parmesan cheese, chopped parsley, garlic powder, onion powder, kosher salt, and black pepper. Whisk these ingredients together until the mixture is well blended and smooth.

Add the cooled rotini pasta to the bowl with the dressing mixture. Gently stir the pasta with a spatula or wooden spoon, ensuring each piece is thoroughly coated.

You can either serve the Lemon Parmesan Pasta Salad immediately or cover the bowl and refrigerate for a couple of hours to allow the flavors to meld.