6 oz (170 g) bittersweet chocolate, chopped
1/3 cup (75 mL) butter
2-1/2 cups (625 mL) rice crisp cereal
1/2 cup (125 mL) salted roasted peanuts, chopped
1 oz (28 g) white chocolate, melted
Line 9-inch (2.5 L) square metal cake pan with parchment paper; set aside.
In large heatproof bowl over saucepan of hot (not boiling) water, melt bittersweet chocolate with butter; remove from heat. Stir in cereal and half of the peanuts; press firmly into pan. Press remaining peanuts firmly onto top. Drizzle with white chocolate. Chill until barely firm, about 30 minutes. With serrated knife, cut into bars. Chill until hard; recut bars. (Make-ahead: Wrap and refrigerate in airtight container for up to 2 weeks or freeze for up to 1 month.)