Bring a large pot of salted water to a boil. Add gnocchi to pot and cook according to package directions, removing them from the pot with a slotted spoon as they come to the surface. Once all of the gnocchi are removed, add baby spinach to the water and boil 1 minute; remove with slotted spoon and drain well.
Meanwhile, place tomatoes in a food processor; process until almost smooth; set aside. Heat oil in a large nonstick skillet over medium-high heat. Add pepper flakes to pan and cook, stirring, for 1 minute. Stir tomatoes and salt into pan. Cook 4 minutes or until thickened.
Stir gnocchi and spinach into tomato sauce. Divide gnocchi mixture among 4 bowls and top each with 2 tablespoons mozzarella cheese and 1 tablespoon basil.