2. To prepare crust, lightly spoon flour into a dry measuring cup; level with a knife. Place flour, pecans, and salt in a food processor; process until pecans are finely ground. Add margarine; pulse 4 times or until mixture resembles coarse meal.
3. With processor on, slowly add 2 tbsp syrup through food chute' processing just until combined (do not form a ball). Place dough on a lightly floured surface; knead lightly 4-5 times (dough will be sticky).
4. Place dough in a 9-inch round removable-bottom tart pan lightly coated with cooking spray. Place a sheet of plastic wrap over dough; press dough into bottom and up sides of pan. Discard plastic wrap. Pierce bottom and sides of dough with a fork; bake at 350 degrees F for 15 minutes or until lightly browned. Cool on a wire rack.
5. To prepare filling, combine ½ cup syrup and cornstarch. Place syrup mixture, sweet potato, and next 6 ingredients in a food processor; process until smooth, scraping sides. Spoon mixture into prepared crust, spreading evenly. Bake at 350 degrees F for 50 minutes or until set. Cool on a wire rack.
6. Place ½ cup syrup in a heavy saucepan; bring to a boil. Cook until reduced to ¹/³ cup; remove from heat. Cool and drizzle about 1½ tsp over each serving.