Heat olive oil in a large saucepan over medium heat. Once the oil is glistening, add the onion and pancetta and cook, stirring occasionally, until onion is softened and pancetta is crispy, about 5 minutes. Add the garlic and cook until fragrant, 1 to 2 minutes more.

Stir in the tomatoes, tomato paste, red pepper flakes (if using), 1 teaspoon of the salt, and vodka. Bring the sauce to a simmer and cook until thickened, about 20 minutes. Slowly stir in the heavy cream.

Meanwhile, bring a large pot of salted water to a boil over high heat. Add the pasta and cook until al dente according to the package instructions. Reserve 1 cup of the pasta cooking water, then drain.

In a medium bowl, beat the egg yolks until smooth. Add the Parmesan and whisk to combine. Slowly pour in 1/4 cup of the reserved pasta water, whisking constantly.

Very slowly add the egg mixture to the tomato sauce and cook, stirring constantly, until fully incorporated, 2 to 3 minutes.

Stir pasta into sauce adding remaining pasta cooking water a little at a time as needed.

Divide between bowls and sprinkle with Parmesan before serving. Top with red pepper flakes and fresh parsley if using.