How to Make It
Cook the spaghetti according to the package directions. Drain, reserving ¼ cup of the cooking water.
Meanwhile, in a food processor, puree 2½ cups of the spinach with the cheese, oil, pine nuts, ¾ teaspoon salt, and ¼ teaspoon pepper.
In a large bowl, toss the spaghetti with the pesto, the shrimp, the remaining 1½ cups spinach, and the reserved cooking water.