Preheat oven to 375 degrees F (190 degrees C). Butter a 2 quart ovenproof casserole dish; set aside.
Cook pasta in a large pot of boiling salted water until al dente. Drain.
Meanwhile, bring half-and-half, basil, and crushed red pepper to a simmer in a heavy, large saucepan over medium high heat. Add cheeses 1 handful at a time, stirring constantly until cheeses are melted and smooth. Remove from heat, and stir in egg yolks. Season with salt and black pepper to taste. Mix in pasta. Spoon into prepared dish.
Bake until heated through, approximately 10 minutes. Serve hot.