Cook the noodles: Bring a large pot of salted water to a boil. Add the noodles and cook according to package directions until just al dente — do not overcook. Drain immediately and rinse thoroughly under cold running water for 30–60 seconds until the noodles are completely cooled and no longer sticky. Toss with 1 tsp sesame oil to prevent clumping and set aside.

Make the peanut sesame sauce: In a large mixing bowl, whisk together the peanut butter, soy sauce, toasted sesame oil, rice vinegar, chili oil, sriracha, and honey until smooth and combined. Add the grated garlic and ginger and whisk again. Add warm water one tablespoon at a time, whisking between additions, until the sauce reaches a pourable, creamy consistency that will coat the noodles. Taste and adjust seasoning — add more soy sauce for saltiness, more vinegar for brightness, more chili oil for heat, or more honey to balance.

Dress the noodles: Add the rinsed, cooled noodles to the bowl with the peanut sesame sauce. Using tongs or two forks, toss thoroughly until every strand is evenly coated. Make sure to get into the bottom of the bowl where the sauce pools — you want full, even coverage.

Chill (optional but recommended): For the best flavor and texture, cover the bowl and refrigerate for at least 15–20 minutes before serving. This allows the noodles to absorb the sauce and the flavors to deepen. If making ahead, refrigerate up to 24 hours and toss again before serving, adding a splash of sesame oil or water to loosen if needed.

Serve and garnish: Divide the dressed noodles into bowls. Top generously with sliced cucumber, shredded carrots, and scallions. Sprinkle with toasted sesame seeds and drizzle with additional chili oil. Add cilantro and crushed peanuts if using. Serve immediately at room temperature or cold straight from the fridge.