01 - Cook the rice vermicelli noodles according to package instructions. Drain thoroughly, rinse under cold water until cool, and set aside to drain completely.
02 - Julienne the carrot and cucumber into thin matchsticks. Slice the red bell pepper into thin strips. Arrange all prepared vegetables, herbs, cooked chicken, and noodles within easy reach of your work station.
03 - Fill a large shallow dish with warm water. Dip one rice paper wrapper into the water for 5-10 seconds until just pliable and flexible. Place the softened wrapper on a clean, damp kitchen towel or cutting board.
04 - Layer ingredients on the bottom third of the wrapper: place one lettuce leaf first, followed by a small handful of noodles, sliced chicken, carrot, cucumber, bell pepper, and 2-3 leaves each of mint, cilantro, and Thai basil. Fold both sides of the wrapper inward toward the center, then roll up tightly from the bottom into a neat cylinder. Repeat with remaining ingredients.
05 - In a small bowl, whisk together hoisin sauce, peanut butter, soy sauce, rice vinegar, sugar, and warm water until completely smooth and well combined. Adjust consistency with additional water if needed. Stir in sriracha if desired. Sprinkle crushed peanuts over the top.
06 - Serve rolls whole or sliced in half diagonally, with dipping sauce on the side. Keep assembled rolls covered with a damp towel until serving to prevent drying out.