Spaghetti Squash Parmesan

large (2½-3 pound) spaghetti squash

extra-virgin olive oil

kosher salt and freshly ground black pepper

panko (Japanese bread flakes)

jar marinara sauce, such as Rao’s

+ 4 tablespoons freshly grated Parmesan cheese, divided

chopped fresh basil leaves, plus extra for serving

ball fresh mozzarella cheese, thinly sliced