Bring a large pot of salted water to a boil and cook the pasta until it’s just al dente, following the package directions. Before draining, scoop out about 1 cup of the cooking water and keep it nearby. Drain the pasta and set it aside.
In the same pot or in a large skillet, combine the ricotta, grated cheese, lemon zest, lemon juice, salt, and black pepper. Stir everything together until the mixture looks evenly blended.
Pour in about ½ cup of the reserved pasta water and whisk or stir until the sauce becomes creamy and smooth.
Add the hot pasta to the sauce and toss well so every piece gets coated. Add a little more pasta water as needed until the sauce reaches a silky consistency.
Fold in the arugula and stir just until it starts to soften from the heat.
Spoon the pasta into a large serving bowl or divide it among individual bowls. Finish with a drizzle of olive oil, more cheese, chili flakes, basil if using, and lemon wedges on the side.