Prepare the peanut sauce by whisking together peanut butter, water, hoisin sauce, lime juice, soy sauce, sugar, chile-garlic paste, garlic, and sesame oil in a bowl.

Boil shrimp for 30 seconds. Drain and pat dry.

Halve each shrimp horizontally.

Cook the rice noodles according to package directions. Drain and set aside.

Soften rice paper wrapper by submerging in hot water for 15 seconds. Place on a damp towel.

Arrange 3 shrimp halves, cut side up, just above the center of the wrapper.

Layer rice noodles over the shrimp.

Add bean sprouts, mint leaves, basil leaves, cilantro sprig, and serrano chiles (if using).

Place cucumber sticks and scallion pieces on either side of the noodle pile.

Roll a lettuce leaf into a cigar shape and place on top of the noodle pile.

Fold the bottom half of the rice paper over the filling.

Fold the sides of the wrapper in.

Roll the wrapper tightly from the bottom to the top.

Place on a rimmed baking sheet and cover loosely with plastic wrap.

Repeat with the remaining wrappers and fillings.

Serve immediately with the peanut sauce for dipping or refrigerate up to 2 hours.