Bring a large pot of salted water to a rolling boil over medium-high heat. Once boiling, add the capellini pasta and cook for about 4-5 minutes, or until al dente. Drain and rinse under cold water to stop the cooking process.

In a mixing bowl, whisk together the juice of two lemons, lemon zest, olive oil, garlic salt, and black pepper until well combined and slightly emulsified.

Add the cooled capellini pasta to the bowl with the dressing. Fold in diced tomatoes and drained capers. Toss everything together until well mixed.

Incorporate chopped parsley and a sprinkle of lemon zest if desired. Toss again to combine.

Serve immediately or cover and refrigerate for at least 30 minutes to allow the flavors to meld.