Step 1: Cook Your Noodles. Bring a large pot of salted water to a rolling boil. Add your chosen noodles and cook according to package directions until al dente. Don't overcook them. Before draining, reserve about 1/2 cup of the starchy pasta water.
Step 2: Prepare the Gochujang Sesame Garlic Sauce. While the noodles are cooking, whisk together the gochujang, soy sauce, rice vinegar, honey (or brown sugar), toasted sesame oil, minced garlic, and grated ginger (if using) in a medium bowl. If the sauce seems too thick, add a tablespoon or two of the reserved hot pasta water until it reaches your desired consistency. Taste and adjust seasonings.
Step 3: Combine and Toss. Drain the cooked noodles well. Add them directly to the bowl with your prepared sauce. Using tongs, toss the noodles thoroughly until every strand is evenly coated. If the noodles absorb too much sauce and become dry, add another splash of the reserved pasta water, a tablespoon at a time, until they are glossy and perfectly coated.
Step 4: Serve and Garnish. Transfer the Gochujang Sesame Garlic Noodles to serving bowls. Garnish generously with chopped scallions and a sprinkle of sesame seeds. For an extra kick, a dash of chili flakes can be added. Serve immediately.