Bring a large pot of salted water to a boil over medium-high heat. Add the ravioli and cook according package instructions. Reserve ½ cup of the pasta cooking water. Drain the ravioli.
While the ravioli is cooking, stir together the sun-dried tomatoes, hazelnuts, arugula, salt and pepper in a large serving bowl. Drizzle in olive oil and gently toss to combine.
Add the ravioli to the sun-dried tomato mixture and toss gently to combine. You may want to use your hands to avoid ripping the ravioli.
Serve and garnish with Parmesan cheese, if desired.