• 1 pound angel hair pasta
• 1 tablespoon olive oil
• 10 ounces pancetta (or bacon would suffice)
• 1.5 cup heavy cream
• 3 egg yolks
• 2.5 cups grated Parmesan/Romano cheese
• 1 teaspoon salt
• 1 teaspoon freshly ground black pepper
• 1 cup sliced mushrooms (optional)

1. Bring a large saucepan of water to a boil. Heat a medium skillet over medium heat. Add the olive oil, mushrooms and pancetta to skillet, and cook until the pancetta is browned, 3 to 4 minutes. Remove skillet from heat, and keep warm.
2. Cook spaghetti in boiling water until al dente, about 8 minutes. While spaghetti is cooking, whisk cream, egg yolks, 2 cups of cheese, salt, and pepper in a medium bowl until combined. Drain pasta, and return to saucepan. Immediately stir in egg-and-cheese mixture until well combined. Add warm pancetta and fat from pan. Toss well. Thin sauce with additional cream, if necessary. Serve immediately, garnished with remaining grated cheese.

Found this online and made a few changes.