Peanut Brittle

Line a baking sheet with parchment paper.

In a medium, deep, heavy saucepan, combine the sugar, corn syrup, water, and salt, pouring everything into the center of the pan to avoid getting sugar on the sides (which can cause crystallization). Set over medium heat and bring to a boil, stirring gently until the sugar dissolves and the sides stay clean.

Clip a candy thermometer to the side of the pan. Continue cooking, without stirring, until the mixture reaches 280°F—this usually takes 8 to 13 minutes, though the exact time will vary depending on your pan. Stir in the peanuts and continue cooking, stirring occasionally, until the thermometer registers 300°F (the hard crack stage), 3 to 5 minutes more. Again, the timing may vary significantly, so keep a close eye on it.

Remove from the heat and quickly stir in the butter and vanilla until melted. Immediately add the baking soda and stir vigorously—the mixture will foam up. Pour the brittle onto the prepared baking sheet and quickly spread it into an even ¼-inch layer with a greased offset spatula. Don’t fuss with it; spread it once and let it be.

Cool completely, about 30 minutes, then break into pieces.