Whole Wheat Spaghetti with Caper Pesto Sauce

Bring a large pot of salted water to a boil. Add spaghetti to pot; cook, stirring frequently the first 3 minutes and then occasionally, until pasta is al dente, about 2 minutes less than recommended on the package. While pasta is cooking, take 1/4 cup pasta water and set aside in a bowl. Meanwhile, make pesto: Combine capers, garlic, anchovies, and parsley in a blender or food processor. Process, stopping to scrape down the sides as needed until parsley is finely chopped. Add oil in a fine stream, blending until creamy. Transfer sauce to a medium bowl; stir in cheese. Drain pasta and transfer to a large bowl. Stir reserved pasta water into pesto. Pour sauce over pasta and mix well to combine. Top with pepper and more cheese if desired. Serve immediately.