01 - Soak rice vermicelli noodles in hot water for 5-7 minutes until tender. Drain thoroughly and rinse under cold water to stop cooking. Set aside in a colander to drain excess moisture.
02 - Julienne the carrot and cucumber, removing cucumber seeds. Tear lettuce leaves into wrapper-sized pieces. Arrange all ingredients on a clean work surface: shrimp (cut side up), lettuce, herbs, carrots, cucumber, and drained noodles.
03 - Fill a large shallow bowl with warm water. Submerge one rice paper wrapper completely for 5-8 seconds until pliable but not mushy. Lay flat on a damp kitchen towel or cutting board, smoothing out any wrinkles.
04 - Layer small amounts of lettuce, noodles, carrot, cucumber, and herbs on the lower third of the wrapper. Place 2-3 shrimp halves cut side up. Fold the bottom edge over filling, fold in both sides, then roll tightly away from you to seal.
05 - Repeat the soaking and rolling process with remaining ingredients to create 8 spring rolls. Place finished rolls on a plate, covering with a slightly damp paper towel to prevent drying.
06 - Whisk peanut butter, hoisin sauce, soy sauce, lime juice, and sriracha in a small bowl. Gradually add warm water, 1 tbsp at a time, until reaching desired consistency. The sauce should be smooth and creamy.
07 - Serve spring rolls immediately with peanut dipping sauce on the side. For best presentation, slice rolls in half diagonally to reveal the colorful filling inside.