Preheat oven to 350°F. Brush rimmed baking sheet with oil. Attach candy thermometer to side of heavy medium saucepan (do not allow tip to touch bottom). Add sugar and 1/4 cup water to saucepan and stir over medium heat until sugar dissolves. Increase heat and boil without stirring until thermometer registers 240°F, occasionally swirling pan and brushing down sides with wet pastry brush, about 4 minutes (time will vary depending on size of pan). Remove from heat. Quickly stir in chili powder, butter, chili sauce, and salt (mixture may bubble). Working quickly, add nuts; stir until coated. Transfer to baking sheet, spreading to separate nuts. Bake until nuts are browned and mixture bubbles, stirring occasionally, about 9 minutes. Cool. Break nuts apart. (Can be made 1 week ahead. Store at room temperature in airtight container.) *Available at Asian markets and in the Asian foods section of some supermarkets.