Bring a large pot of water to a boil, add the sea salt, and cook spaghetti until al dente according to package directions.
While the pasta cooks, place the diced pancetta in a large skillet over medium heat and sauté until the fat renders and the meat is golden and crispy.
In a small mixing bowl, whisk together the whole egg, liquid egg whites, and grated Pecorino Romano cheese until smooth.
Before draining the pasta, reserve approximately 0.25 cup of the starchy cooking water.
Drain the spaghetti and immediately add it to the skillet with the pancetta, tossing well to coat the strands in the rendered fat.
Remove the skillet from the heat source entirely to prevent the eggs from scrambling.
Pour the egg and cheese mixture over the pasta, stirring rapidly and constantly to create a creamy, emulsified sauce.
Slowly add small splashes of the reserved pasta water as needed to reach a glossy, silk-like consistency.
Season generously with freshly cracked black pepper and garnish with chopped fresh parsley before serving.