Bring a large pot of salted water to a boil. Cook the udon noodles according to package directions, typically 3-5 minutes for fresh or 8-10 minutes for dry. Drain in a colander and rinse under cold running water until the noodles are completely cool. Shake off excess water and set aside.

While the noodles cook, prepare the sauce. In a medium bowl, whisk together the creamy peanut butter, soy sauce, rice wine vinegar, lime juice, honey, and toasted sesame oil until smooth and well combined. The mixture should be pourable like a dressing. If it is too thick, add water or vegetable broth 1 tablespoon at a time, whisking until you reach the desired consistency.

In a large mixing bowl, combine the chilled noodles with the peanut sauce. Use a rubber spatula or salad tongs to toss until every strand is evenly coated.

Add the thawed edamame, matchstick carrots, chopped peanuts, sliced shallot, green onions, and Thai basil. Toss everything together until well distributed.

Taste and adjust seasoning if needed. Serve immediately, topped with dollops of spicy chili crisp for heat and crunch if desired.