Step 1: Wash and thoroughly dry the scallions. Slice them thinly, separating the white and light green parts from the darker green tops. Keep them separate.
Step 2: In a large pan or wok, add 1 cup of neutral oil over medium-low heat. Add the white and light green parts of the sliced scallions. Cook slowly, stirring occasionally, for 10-15 minutes, until they soften and turn light golden.
Step 3: Add the darker green parts of the scallions to the pan. Continue to cook, stirring more frequently, for another 10-15 minutes, until all scallions are deeply golden-brown and crispy. Be careful not to burn them. Remove the pan from the heat.
Step 4: While the scallions are cooking, boil 1 pound of noodles according to package directions in a large pot of salted water until al dente. Drain well and rinse briefly with warm water to prevent sticking.
Step 5: Carefully strain the hot oil into a heat-proof bowl, separating the crispy caramelized scallions. Set the crispy scallions aside. To the strained scallion oil, add 1/4 cup light soy sauce, 1 tablespoon dark soy sauce, 1 tablespoon sugar, and 1/2 teaspoon white pepper. Stir until the sugar is dissolved.
Step 6: Return the cooked and drained noodles to the large pan or a clean large bowl. Pour the scallion oil sauce over the noodles. Toss thoroughly until every noodle strand is evenly coated.
Step 7: Divide the Caramelized Scallion Oil Noodles among serving bowls. Garnish generously with the reserved crispy caramelized scallions and, if desired, a sprinkle of fresh scallions or a drizzle of chili oil. Serve immediately.