**Cook the Pasta**
Bring a large pot of salted water to a boil. Add the pasta and cook according to package instructions, or until al dente. Drain, reserving about 1/2 cup of pasta water. Set the pasta aside.
**Prepare the Salmon**
While the pasta is cooking, heat the olive oil in a skillet over medium-high heat. Season the salmon fillets with salt, pepper, and lemon zest (if using). Add the salmon to the skillet and cook for about 4-5 minutes per side, or until the salmon is cooked through and flakes easily with a fork. Remove the salmon from the skillet and set aside to cool slightly.
**Make the Pesto Sauce**
In a food processor or blender, combine the basil, pine nuts, garlic, Parmesan cheese, olive oil, salt, and pepper. Blend until smooth, scraping down the sides as needed. If the pesto is too thick, you can add a little pasta water or olive oil to reach your desired consistency. Taste and adjust seasoning with more salt, pepper, or lemon juice, if desired.
**Assemble the Pasta**
Flake the cooked salmon into bite-sized pieces using a fork. In a large bowl, toss the cooked pasta with the pesto sauce, adding pasta water a little at a time to help the sauce coat the pasta evenly. Add the flaked salmon and gently toss to combine.
**Serve**
Divide the pasta between serving bowls. Top with extra grated Parmesan cheese and fresh basil leaves, if desired. Serve immediately and enjoy!