Cook the noodles in a large pot of boiling salted water according to package instructions until al dente. Drain and set aside.
In a small bowl, whisk together the soy sauce, Chinkiang or rice vinegar, brown sugar, chili garlic sauce, and cornstarch until smooth; set the sauce aside.
Heat the sesame oil in a large skillet or wok over medium-high heat.
Add the cubed chicken to the hot skillet and cook, stirring occasionally, until browned and no longer pink in the center, about 5–7 minutes.
Add the minced garlic and the dried chili peppers to the pan and cook for about 1–2 minutes until fragrant and the peppers soften slightly.
Pour the prepared sauce into the skillet, stir to coat the chicken and peppers, and cook until the sauce thickens, about 1 minute.
Add the drained noodles and the roasted peanuts to the skillet and toss everything together until the noodles are evenly coated in the sauce and heated through.
Garnish with chopped green onion and red pepper flakes before serving.