Be sure to use a heavy Dutch oven and a candy thermometer, and make pralines on a day when the weather is dry—humidity can make them grainy.
2 cups pecan halves and pieces
3 cups firmly packed light brown sugar
1 cup whipping cream
1/4 cup butter
2 tablespoons light corn syrup
2 (1-oz.) unsweetened chocolate baking squares
1 teaspoon vanilla extract
How to Make It
Preheat oven to 350°. Bake pecans in a single layer in a shallow pan 8 to 10 minutes or until toasted and fragrant, stirring halfway through. Cool completely (about 15 minutes).
Meanwhile, bring brown sugar and next 3 ingredients to a boil in a heavy Dutch oven over medium heat, stirring constantly. Boil, stirring occasionally, 6 to 8 minutes or until a candy thermometer registers 236° (soft ball stage). Remove sugar mixture from heat. Add chocolate baking squares to sugar mixture. (Do not stir.)
Let sugar mixture stand until candy thermometer reaches 150° (20 to 25 minutes). Stir in vanilla and pecans 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; let stand until firm (10 to 15 minutes).