1 cup granulated sugar
1 cup peanuts
1/2 cup light corn syrup
1/4 cup water
2 tablespoons unsalted butter, softened
1 teaspoon baking soda
1/4 teaspoon salt
1/2 teaspoon vanilla extract* Helpful Gadgets: Candy thermometer
Grease a large baking sheet. Put your baking soda, vanilla extract and butter into three separate bowls and place by work area.
In a large saucepan (2-4 quarts) over medium heat, combine the water, corn syrup, salt and sugar. Stir until the sugar is dissolved and the liquid is completely clear, then add the peanuts and stir to incorporate fully. Make sure to have a candy thermometer in place to gauge temperature.
Stir frequently until the temperature reaches 300º F (150º C; cracking stage). Remove from heat and quickly mix in the butter, baking soda and vanilla. The mixture will begin to bubble and foam up.
Immediately pour onto baking sheet. Using two forks or wearing gloves, pull the mixture into a large rectangle. Try to pull it as thinly as possible.
Let cool, then break into pieces.
Store in an airtight container for up to 10 days.