In a medium bowl, whisk together 2 eggs and 2 yolks until smooth, whisk in 3 ounces shredded Gouda, 1 ounce grated Parmesan, and 7 turns black pepper.
Bring a large pot of water to a boil; season liberally with salt (about 2 tablespoons). Add 12 ounces spaghetti and cook until al dente, about 1 minute less than the package directions, stirring often to prevent sticking. Reserve 2 cups pasta water then drain.
Meanwhile, heat 1 tablespoon oil in a 12-inch sauté pan over medium, add 4 ounces diced pancetta and cook, stirring occasionally, until lightly golden-brown and just starting to crisp, about 5 minutes; reduce heat to low.
Slowly whisk ¼ cup reserved pasta cooking water into cheese and egg mixture.
Immediately after draining pasta, add hot pasta to pan with pancetta and briefly toss with tongs.
Add egg mixture, tossing continuously (gently to avoid breaking the noodles), until pasta is well coated, about 3 minutes; add additional reserved pasta cooking water by ¼ cup to reach desired creamy consistency (you may end up using quite a bit of the reserved cooking water and that’s OK).
Serve carbonara hot, sprinkled with additional black pepper to taste.