2 lbs. light brown sugar
4 Tbs. light Karo syrup
1 cup evaporated milk
4 oz. butter
2 tsp. pure vanilla extract
5 cups raw pecan halves
Line two rimmed baking sheets with Silpats or waxed paper. Place a wire cooling rack on top of each. (Lining the baking sheets will make it easier to clean up the praline drippings.)
Combine the brown sugar, Karo syrup, and evaporated milk in a 5 1/2-quart heavy bottomed pot and bring to a boil over medium heat. Boil, stirring constantly, for three minutes. Remove the pot from the heat and stir in the butter, vanilla, and pecans.
Let the mixture stand in the pot until it thickens and loses its gloss, then pour it out on the racks on the baking sheets. Using forks, separate the pecans so that they will set up individually. Leave them on the wire racks for at least four hours, or until they are dry to the touch. Stored in sealed plastic bins in a cool place (not refrigerated), the pecans will keep for several weeks.