Active Time

　　45 min

　　Total Time

　　1 3/4 hr

　　The transformation of butter, sugar, and salt into toffee is culinary alchemy at its best. This version is studded with cocktail peanuts and a decadent layer of bittersweet chocolate.

　　

Ingredients

Makes about 3 pounds

　　4 sticks (1 pound) unsalted butter, cut into pieces

　　2 cups sugar

　　1/4 teaspoon salt

　　4 cups whole cocktail peanuts plus 1 cup chopped (1 pound 10 ounces)

　　1 cup chopped cocktail peanuts

　　7 to 8 ounces 70%-cacao bittersweet chocolate, finely chopped

　　Equipment: a 15- by 10- by 1-inch baking pan; a candy thermometer; a metal offset spatula

　　1 candy thermometer

　　1 metal offset spatula

　　

Step 1

Butter baking pan and put on a heatproof surface.

　　

Step 2

Bring butter, sugar, and salt to a boil in a 4- to 5-quart heavy pot over medium-high heat, whisking until smooth, then boil, stirring occasionally, until mixture is deep golden and registers 300°F (hard-crack stage) on thermometer, 15 to 20 minutes.

　　

Step 3

Immediately stir in whole peanuts, then carefully pour hot toffee into center of baking pan. Spread with spatula, smoothing top, and let stand 1 minute, then immediately sprinkle chocolate on top. Let stand until chocolate is melted, 4 to 5 minutes, then spread over toffee with cleaned spatula. Sprinkle evenly with chopped peanuts, then freeze until chocolate is firm, about 30 minutes. Break into pieces.

　　Cooks' note:

　　Toffee keeps, layered between sheets of parchment paper, in an airtight container at cool room temperature 2 weeks.