Bring a pot of lightly salted water to a boil. Add shrimp and cook until pink and opaque, about 2 to 3 minutes. Drain, cool, and slice shrimp in half lengthwise.

Cook vermicelli noodles according to package instructions, then drain and cool. Chop herbs and scallions. Arrange all fillings separately for easy assembly.

Fill a large shallow dish with warm water. Dip one rice paper wrapper for 10 to 15 seconds until just soft, then lay flat on a clean surface.

On the lower third of the wrapper, layer lettuce, vermicelli noodles, bean sprouts, cilantro, mint, scallions, and 3 to 4 shrimp halves with the pink side down.

Fold the bottom over the filling, fold in the sides, and roll tightly like a burrito. Repeat with remaining wrappers.

Whisk hoisin sauce, peanut butter, rice wine vinegar, soy sauce, sesame oil, garlic powder, and onion powder until smooth. Thin with 1 to 2 teaspoons warm water if needed.

Serve rolls fresh with the dipping sauce on the side, garnished with crushed peanuts or chili flakes if desired.