1 1/2 teaspoons plus 1 1/2 cups butter (no substitutes)
2 cups peanut butter
1 3/4 cups granulated sugar
3 tablespoons light corn syrup
3 tablespoons water
1 1/2 cups salted peanuts, coarsely chopped
1/2 cup semisweet
Butter the bottom and sides of a 15 x 10 x 1-inch baking pan with the 1
1/2 teaspoons butter. Sprinkle with 1 cup peanut butter chips; set aside.
In a heavy saucepan, bring sugar, corn syrup, water and remaining 1 1/2
cups butter to a boil over medium heat, stirring constantly. Cook and stir until
butter is melted. Cook, without stirring, until a candy thermometer reads 300
degrees F (hard-crack stage).
Remove from heat; stir in peanuts.
Quickly pour onto prepared baking pan; sprinkle with chocolate chips and
remaining peanut butter chips. With a knife, gently swirl softened chips over
top of brittle.