Cook pasta al dente according to package instructions in a large stockpot of generously-salted water. Meanwhile, as the pasta is cooking, whisk together the soy sauce, rice vinegar, sesame oil, ground ginger, chili garlic sauce, garlic powder and black pepper together in a bowl until combined. Once the pasta is ready, drain it. Then immediately toss the pasta with the sauce and green onions until combined. Serve warm or cold, sprinkled with your desired toppings. Or transfer to a sealed container and refrigerate for up to 4 days.
