Place a large pot of water over high heat. Add 1 tablespoon of salt and bring the water to a boil. Add the spaghetti and cook following the package directions. Drain well.
Heat the vegetable oil in a small skillet or saucepan over medium heat. Add the garlic and chili crisp and cook for 1 to 2 minutes, until aromatic. Remove the pan from the heat and add the soy sauce, vinegar, brown sugar, and sesame oil.
Steam the peas and carrots, if using.
Combine the hot, cooked spaghetti with the sauce mixture, green onions, and hot steamed peas and carrots (if using).
Garnish the sesame noodles with chopped roasted peanuts or sesame seeds.