Step 1In a bowl, whisk together the hoisin sauce, peanut butter, rice vinegar, soy sauce, chili garlic sauce and toasted sesame oil. Taste and adjust the seasoning if desired with additional soy sauce. This makes a a scant ½ cup dipping sauce. Set aside until ready to serve.
Step 1Fill a shallow bowl with very warm water. Soak one rice paper wrapper in the water until pliable enough to be rolled, about 30 seconds. Transfer the wrapper onto a clean cutting board.
Step 2Arrange the fillings along the bottom third of the wrapper leaving about a 1-inch margin on either end of the filling. I use about 2 tablespoons of the rice noodles; equal amounts of the cucumber, carrot, bell pepper, mango and scallions; a few fresh mint, basil and cilantro leaves; 2 avocado slices; and a butter lettuce leaf for each roll. Be careful not to overfill the wrappers or they will be hard to roll.
Step 3Fold the wrapper over the filling and start rolling it up. About halfway through the roll, stop and fold in the sides, burrito style, then finish rolling until you have a tight roll. Transfer the finished roll to a clean plate, seam side down and drape with a damp kitchen towel while you assemble and roll the remaining summer rolls. Once all of the rolls are finished, serve immediately with the dipping sauce alongside.