If you can't find Thai basil, do not substitute regular basil; its flavor is too gentle to stand up to the other, more assertive flavors in the filling. Mint makes a better substitute. If you are unable to obtain fish sauce, substitute an equal amount of rice vinegar plus 1/4 teaspoon salt. Spring rolls are best eaten immediately, but they can be held for up to 4 hours in the refrigerator, covered with a clean, damp kitchen towel.

Directions
1. Combine sugar, fish sauce, and lime juice in small bowl; set aside.

2. Bring 2 quarts water to boil in medium saucepan. Stir in salt and rice vermicelli. Cook until noodles are tender but not mushy, 3 to 4 minutes. Drain noodles and rinse under cold running water until cool. Drain again and transfer to medium bowl; toss 2 tablespoons fish sauce mixture with noodles and set aside.

3. Combine carrot, peanuts, and jalapeño in small bowl. Add 1 tablespoon fish sauce mixture; toss to combine. Toss cucumber in remaining 1 tablespoon fish sauce mixture.

4. Place lettuce on platter. Spread clean, damp kitchen towel on work surface. Fill 9-inch pie plate with 1 inch room-temperature water. Working one at a time, immerse each wrapper in water until just pliable, about 10 seconds; lay softened wrapper on towel. Scatter 6 Thai basil leaves and 6 cilantro leaves over wrapper. Arrange 5 cucumber sticks horizontally on wrapper; top with 1 tablespoon carrot mixture, then arrange about 21/2 tablespoons noodles on top of carrot mixture. Wrap spring roll; set on 1 lettuce piece on platter. Cover with second damp kitchen towel; repeat with remaining ­wrappers and filling. Serve with dipping sauce, wrapping lettuce around exterior of each roll.