For the manicotti: Preheat the oven to 375 degrees F. Spray a 9- by 11-inch oval or rectangle baking dish with vegetable oil cooking spray.
Bring a large pot of boiling salted water to a boil over medium-high heat. Add the oil and pasta. Cook until just tender, but still firm to the bite, stirring occasionally, 5 to 7 minutes. Drain and cover with plastic wrap to prevent the pasta from drying out.
In a large nonstick skillet, cook the bacon until crisp and brown, about 7 minutes. Drain on paper towels and set aside to cool.
In a large bowl, add the cooled bacon, the spinach, ricotta, Parmesan, 1/2 teaspoon salt, the pepper, nutmeg and egg. Stir until well combined. Using a small spoon, fill the manicotti tubes with the ricotta mixture.
For the sauce: Bring the cream, milk, flour, salt, pepper and nutmeg to a simmer in a heavy, medium saucepan over medium heat. Add the mozzarella in batches, constantly whisking, until the sauce is thick and smooth. Reduce the heat to low and simmer 1 minute, whisking occasionally. Whisk in the tomato basil sauce.
Pour half of the sauce on the bottom of the prepared baking dish. Arrange the manicotti in a single layer on the sauce. Pour the remaining sauce on top of the manicotti and top with the mozzarella. Drizzle with olive oil and cover the dish with foil. Bake until heated through and bubbling, 20 to 25 minutes.