How to Make It
Bring a large pot of water to a boil. In a large, deep skillet, heat the oil. Add the garlic and cook over moderate heat until golden, about 3 minutes. Discard the garlic. Add the pancetta to the skillet and cook over moderately high heat, stirring occasionally, until golden and crisp and the fat has been rendered, about 5 minutes. Using a slotted spoon, transfer the pancetta to a bowl.
Pour off all but 2 tablespoons of the fat from the skillet. Add the cream and scrape up any browned bits from the bottom of the skillet, then pour into a medium bowl. Whisk in the egg yolks and 1/3 cup of the Parmesan cheese.
Add salt to the pot of boiling water. Add the baby peas and cook just until tender, about 1 minute. Using a slotted spoon, transfer the cooked peas to a bowl.
Add the spaghetti to the boiling water and cook until al dente; drain. Return the pasta to the pot and add the cream mixture, pancetta and peas. Season with salt and pepper and toss until the sauce coats the spaghetti. Transfer to bowls and serve immediately with the remaining Parmesan.