1. To make the sauce: In a small saucepan, mix the vinegar, sugar, water, garlic, and chili paste together. Bring to a simmer over medium heat, stirring to dissolve the sugar. Remove from heat and let stand until cool. (The sauce can be prepared up to 1 day ahead and stored at room temperature.)

2. To make the spring rolls: In a medium bowl, cover the noodles with very hot water. Let stand until the noodles are soft and supple, about 10 minutes. Drain well in a sieve. Using kitchen scissors, snip through the bean threads in the sieve to cut them into more manageable tengths. Place in a bowl, cover with plastic wrap, and set aside.

3. Heat a large wok or skillet over high heat. Add the oil and tilt to coat the inside of the pan. Add the shallots and gartic and stir-fry until fragrant, about 15 seconds. Add the carrot and stir-fry until crisp-tender, about 1 minute. Add the crab, bean sprouts, cilantro, fish sauce, sugar, and chili or Tabasco sauce and stir-fry until heated through, about 2 minutes. Remove from heat and place in a shallow dish. Stir in the bean threads. Let coot completely.

4. Preheat the oven to 200°F. Line a baking sheet with waxed paper. Place an egg roll wrapper on a work surface, with the points at 12, 3, 6, and 9 o'clock. Place about 1/4 cup filliing on the bottom third of the wrapper and form it into a log that comes no closer than 1/2 inch to the edges of the wrapper. Fold up the bottom point and roll up the egg roll, folding in the side points as you roll it into a tight cylinder. Place a dab of water on the last point to adhere it to the roll. Place the spring roll, seam-side down, on the waxed paper. Repeat with the remaining filling and wrappers.

5. Place a large wire cake rack over a jelly roll pan. In a deep dutch oven, heat vegetable shortening over high heat to a depth of 2 to 3 inches and heat it to 365°F In batches, without crowding, deep-fry the spring rolls until golden brown, about 3 minutes. Using a wire mesh skimmer, transfer to the wire rack and keep warm in the oven while deep-frying the remaining spring rolls. Serve immediately, with small bowls of the garlic sauce for dipping.