How to Make It
Bring brown sugar and evaporated milk to a boil in a heavy 4-qt. saucepan over medium heat, stirring constantly. Boil, stirring occasionally, 4 to 6 minutes or until a candy thermometer registers 236˚F (soft ball stage). Remove sugar mixture from heat.
Let sugar mixture stand until candy thermometer reaches 150˚F (20 to 25 minutes). Stir in pecans and vanilla using a wooden spoon; stir constantly 1 to 2 minutes or just until mixture begins to lose its gloss.
Quickly drop by heaping tablespoonfuls onto wax paper, and let stand until firm (10 to 15 minutes).