Step 1

Preheat oven to 375°F. Cut off top 1/2 inch of garlic head, exposing cloves. Place garlic head, cut side up, on sheet of foil and drizzle with 1/2 teaspoon olive oil. Wrap garlic in foil. Roast until garlic is soft, about 40 minutes. Let stand until cool enough to handle. Squeeze garlic into small bowl.

Step 2

Cook pasta in large pot of boiling salted water until just tender but still firm to bite, stirring occasionally. Meanwhile, cook bacon strips and chopped onion in heavy large skillet over medium-high heat until golden brown, stirring occasionally, about 12 minutes. Add chicken broth, remaining 5 1/2 teaspoons olive oil, and roasted garlic. Bring mixture to simmer, stirring occasionally. Add radicchio, spinach, and basil and stir to combine. Simmer just until radicchio and spinach wilt, about 1 minute.

Step 3

Drain pasta and return to same pot. Add radicchio-spinach mixture to pasta. Add 1 cup grated Parmesan cheese and crushed red pepper; toss to coat. Season pasta to taste with salt and pepper and serve, passing additional Parmesan cheese alongside.