Bring 2 cups of water to a boil in a medium-sized pot. Add the noodles from the Samyang Buldak Ramen package and cook for 4 minutes, or until al dente. Drain the noodles, reserving 1/4 cup of the cooking water, and set aside.

In a small mixing bowl, whisk together the egg yolk, Parmesan cheese, and heavy cream until smooth. Set this mixture aside.

In a frying pan over medium heat, melt the butter. Add the diced bacon and sauté until crispy, about 5 minutes. Add the minced garlic and cook for another 30 seconds until fragrant.

Reduce the heat to low and add the cooked noodles to the frying pan with the bacon and garlic. Toss to combine.

Pour the reserved 1/4 cup of cooking water into the pan along with the carbonara mixture. Stir quickly and continuously to coat the noodles evenly, ensuring the sauce thickens without scrambling the egg yolk.

Sprinkle in the black pepper and red pepper flakes (if using) for extra spice. Add the Buldak sauce packet from the ramen package and toss until the noodles are well-coated and the flavors are fully incorporated.

Serve immediately, garnished with extra Parmesan cheese if desired.