In a blender, chop pignoli nuts and garlic until finely minced. Add cheese, lemon zest and arugula. Slowly add olive oil in a steady stream to fully incorporate. Blend until smooth.
Once boiling, add pasta and cook for al dente texture, according to package instructions. Drain, reserving 1/2 cup of pasta water to finish sauce, if necessary. Quickly toss hot pasta with pesto to warm sauce without cooking.