Bring a large pot of salted water to a boil. Add the pasta and cook as the label directs.
Meanwhile, heat the olive oil in a saucepan over medium heat. Add the garlic and red pepper flakes and cook, stirring, until the garlic softens, about 1 minute. Add the tomatoes, parmesan rind, 1/2 cup water and half of the basil. Bring the sauce to a boil, then stir and reduce the heat to medium low; simmer 15 minutes. Season with salt.
Increase the heat under the sauce to medium high, add the scallops and cook, stirring occasionally, until opaque, about 5 minutes. Remove the parmesan rind, add the remaining basil and season with salt and more red pepper flakes.
Drain the pasta and add to the skillet with the sauce; toss. Divide the pasta among bowls, drizzle with olive oil and top with more basil.