3. Step
Add the remaining 1 tablespoon oil to the pan with the sauce. Add tomatoes; cook over medium-high heat, stirring occasionally, until beginning to soften, about 30 seconds. Add spinach, in batches, stirring constantly until wilted, about 1 minute. Add the shrimp and any juices, the pasta, pine nuts, salt and pepper; stir until just combined. Stir in Parmesan and 1/4 cup of the reserved cooking water, adding additional cooking water in 1/4-cup increments as needed so that pasta is coated with sauce. Add butter; toss the mixture until the butter melts. Garnish with additional Parmesan and pine nuts, if desired.