Prepare the dipping sauce by mixing together peanut butter, vinegar, soy sauce, maple syrup, sesame oil, garlic, and red pepper flakes together in a small food processor or blender. Add warm water 1 tablespoon at a time, to thin the sauce to a dipping consistency.
Bring a pot of water to a rolling boil. Add the vermicelli noodles to the boiling water, turn off the heat and allow the noodles to sit in the hot water, according to package directions. This is about 5-10 minutes depending on the brand. Drain and rinse the noodles with cold water.
Slice the mangoes, red pepper, and cucumber into thin strips. Shred or slice the carrot. Thinly slice the cabbage. Remove cilantro and mint leaves from stems.
Prepare station for spring rolls by gathering all the prepared fillings (vegetables, herbs, noodles, mango, and shrimp) and filling a shallow pan (a pie pan or 9″ round cake pan works great) with an inch of warm water. Have a lint-free tea towel ready as well.
Place one spring roll wrapper in the water for 15-20 seconds, until JUST pliable, but still has some structure. Carefully remove from the water and lay it flat on the towel.
Leaving about 1 inch of open rice paper around the edges, cover the lower third of the paper with a few pieces of the torn lettuce. Arrange a small handful of rice noodles, some cabbage, a few strips of carrot, cucumber, red pepper, and mango over the center of the lettuce leaf. Top with 2 mint leaves and 2 cilantro leaves.
Arrange 3 pieces of shrimp about right above the vegetable/herb filling. Make sure that the pink side of the shrimp is facing down.
Grab the lower edge of the rice paper and tightly roll up the spring roll to the shrimp. Once you have reached the shrimp, fold in the left and right sides. Finish rolling up the spring roll all the way to the end.
Repeat the rolling process with the rest of the ingredients.
Cut the spring rolls on a diagonal and serve the spring rolls with the dipping sauce.
To prepare in advance: wrap rolls individually in plastic wrap or parchment paper and layer in an airtight container. Store up to 2-3 days. However, best served within 24 hours.Nutritional information is based on 1 spring roll served with 2 tablespoons of sauce.