Cook the pasta according to the package directions. Reserve 3/4 cup of the cooking water; drain the pasta and return it to the pot.
Meanwhile, cook the oil, garlic, red pepper, and 1/4 teaspoon salt in a small pot over medium heat, stirring occasionally, until fragrant and sizzling, 2 to 3 minutes. Remove from heat.
Add the tomatoes, ricotta, 1/2 teaspoon salt, and 1/2 cup of the reserved cooking water to the pasta; toss to coat. (Add more cooking water as needed to loosen the sauce.)
Serve topped with the chili oil and basil.