To make the peanut dipping sauce, combine the peanut butter, hoisin sauce, soy sauce, water, sugar, sesame oil, and lime juice in a bowl and mix using a whisk. Add chili garlic paste if desired.
Boil shrimps until fully cooked, about 40 seconds. Drain off excess water and let cool. Cut shrimps into two lengthwise.
Boil glass noodles (mung bean) for about 2 minutes or until transparent and cooked. Drain off excess water. Season with 1 1/2 tbsp of fish sauce and some salt and pepper to taste.
Cut carrots into very thin 7-8 cm long sticks. Season with vinegar and sugar and set aside. Cut cucumber into sticks and cut lettuce leaves into two, if they are too large (should be about 1/4 of the size of the rice paper).
To make the spring rolls, soften the rice papers one by one with warm water. Lay one on a flat surface. Place 1 or 2 lettuce leaves at the bottom of the paper and place cucumber, carrots, and glass noodles on top of the lettuce. In the middle of the paper, place 4-5 coriander leaves in a row, parallel to the lettuce. At the top of the paper, place 4 shrimp halves in a row, parallel to the corianders and lettuce. To wrap, start by folding from the bottom of the rice paper, covering the lettuce, glass noodles, cucumbers, and carrots. Fold sides inward, and tightly roll the wrapper starting from the bottom where the lettuce is. Repeat steps for each roll. Serve with peanut dipping sauce.