Begin by bringing a large pot of salted water to a boil. Once boiling, add spaghetti and cook until al dente, around 8-10 minutes. Reserve ½ cup of the pasta water, then drain the spaghetti.

While the pasta cooks, whisk together egg yolks and whole egg in a bowl. Gradually stir in freshly grated Parmesan cheese until fully combined. Set aside.

In a skillet over medium heat, fry chopped bacon or pancetta until crispy, around 4-5 minutes. Remove bacon and drain excess fat, leaving about 1 tablespoon in the pan.

In the same skillet, sauté sliced mushrooms over medium heat for about 5 minutes until golden brown and tender.

Return crispy bacon to the pan, then add drained spaghetti, tossing with the mushroom and bacon mixture. Pour in half of the reserved pasta water.

Remove the skillet from heat and quickly add the creamy egg and cheese mixture, stirring vigorously to ensure an even coating. Adjust thickness with remaining pasta water if needed.

Season with salt and freshly cracked black pepper as desired. Serve immediately, garnished with additional Parmesan cheese and black pepper.