1. Place sugar and 2 tablespoons water in a small saucepan over low heat; cook for 8 minutes or until sugar dissolves. Strain through a fine sieve over a bowl, and discard solids. Cool completely. Combine tamarind paste with remaining 2 tablespoons water, stirring until smooth. Combine sugar mixture and tamarind mixture in a large zip-top plastic bag; seal. Set aside.
2. Heat a small skillet over medium-high heat. Add coriander, cumin, and fennel seeds; cook for 2 minutes, shaking pan occasionally. Cool. Place mixture in a spice or coffee grinder, and process until finely ground. Place the galangal, lemongrass, shallots, candlenuts, garlic clove, and red chile in a food processor, and process until finely chopped.
3. Add galangal mixture, coriander mixture, turmeric, and salt to sugar mixture; seal. Knead to combine. Add beef to bag, turning to coat; seal. Marinate in refrigerator for 1 hour, turning twice. Add oil to bag, turning to coat; seal. Marinate in refrigerator overnight, turning occasionally.
4. Preheat grill to medium-high heat.
5. Remove beef from bag; discard marinade. Thread beef evenly onto each of 32 (8-inch) skewers. Place skewers on grill rack coated with cooking spray. Cook 1 minute on each side or until desired degree of doneness. Serve with Peanut Dipping Sauce.