Bring a large pot of salted water to a boil and cook the spaghetti according to the package instructions until al dente. Do not drain the pasta once it is cooked, as you'll use the pasta water later in the recipe. I like to occasionally stir the pasta while it boils to prevent it from sticking together.

While the pasta is boiling, cook the bacon in a large skillet over medium heat until it is cooked through and slightly crispy. Once cooked, remove the bacon from the skillet, transfer to a plate lined with paper towels, and crumble it into bite-sized pieces. Carefully drain all but about 3-4 tablespoons of the bacon grease from the skillet for use in the next step.

Return the skillet with bacon grease to the stovetop and reduce the heat to low. Add the garlic, either minced or thinly sliced, and sauté until it becomes golden brown and fragrant, being careful not to burn it. Using low heat here helps release the garlic’s flavor into the fat, making the sauce richer.

In a bowl, beat together the eggs, heavy cream, and a generous amount of black pepper. Stir in about half of the grated Parmigiano Reggiano cheese. Add a ladle or two of the hot pasta water from the pot to the mixture and stir well. This tempers the egg mixture and prevents the eggs from scrambling—one of my favorite pasta tricks for a creamy sauce.

Using tongs, transfer the cooked spaghetti directly from the pot to the skillet with the garlic. Add the crumbled bacon from Step 2, the egg and cheese mixture from Step 4, and the remaining grated cheese. Toss everything together over low heat until evenly combined and the sauce is creamy. If the pasta seems a bit dry, add a little more hot pasta water or a splash of heavy cream to adjust the consistency.

Serve the pasta immediately while it’s hot and creamy. Garnish with additional black pepper and extra grated cheese to taste. For a richer flavor, I like to add a final sprinkling of fresh cheese right before serving.