In a large mixing bowl, combine peanut butter, soy sauce, rice vinegar, garlic chili oil, gochugaru, and sugar. Add warm water until smooth and creamy.

Bring salted water to a boil and cook wheat noodles for 5-7 minutes until al dente. Drain in a colander.

Transfer the drained noodles back into the pot, add the peanut sauce, and stir to coat thoroughly. Adjust sauce thickness with reserved noodle water if necessary.

Distribute onto plates and top with spring onions, coriander, sesame seeds, and sesame oil. Serve immediately.