Start by bringing a large pot of salted water to a boil. Add your spaghetti (or other pasta of your choice) and cook according to the package instructions, usually around 8-10 minutes for al dente texture. Make sure to stir occasionally to prevent the pasta from sticking.

Once the pasta is cooked, reserve about 1 cup of pasta cooking water before draining. This starchy water will be used to create the creamy sauce for your Carbonara. Drain the pasta and set it aside.

While the pasta is cooking, cut the guanciale (or pancetta) into small cubes or strips. In a large pan, heat a drizzle of olive oil over medium heat. Add the guanciale and cook for about 3-5 minutes until it becomes crispy and golden. If you want to add garlic for extra flavor, you can toss in a smashed garlic clove at this stage, but remember to remove it before adding the pasta.

The guanciale should render its fat during this step, creating a delicious base for your Carbonara sauce. Once crispy, remove the pan from the heat and set aside to keep the guanciale warm.

In a large mixing bowl, whisk together the egg yolks, grated Pecorino Romano, and Parmesan cheeses. Add a generous amount of freshly cracked black pepper to the mixture for that signature Carbonara flavor. The eggs and cheese will form the base of your sauce, which will get creamy when mixed with the hot pasta.

You can adjust the amount of cheese based on your preferences. For a sharper flavor, increase the amount of Pecorino, or add more Parmesan for a nuttier taste. The key is to create a smooth, well-combined mixture.

Once your pasta is cooked and drained, immediately add it to the pan with the crispy guanciale. Toss them together to coat the pasta in the rendered fat, ensuring the guanciale is evenly distributed.

Now, it’s time to bring the dish together. Slowly pour the egg and cheese mixture over the pasta while continuously tossing or stirring. This will help prevent the eggs from scrambling and create a velvety sauce. The residual heat from the pasta and guanciale will cook the egg yolks, creating a luscious, creamy coating on each strand of pasta.

If the sauce feels too thick, you can add a little bit of the reserved pasta cooking water to loosen it up. Add the water in small amounts, stirring well until you achieve the desired creamy consistency. Keep in mind that the sauce should coat the pasta without being runny.

Once your Spaghetti Carbonara is perfectly coated in the creamy sauce, it's ready to be served. Plate your pasta and top it with additional grated Pecorino Romano, Parmesan cheese, and a sprinkle of freshly cracked black pepper. You can also garnish with a few small crispy pieces of guanciale for extra texture and flavor.