Peppermint Bark

Line a 15 1/2- by 10 1/2-inch jelly roll pan with nonstick foil or parchment paper, leaving a 2-inch overhang on 2 sides. In a microwave-safe bowl, melt the bittersweet chocolate on high, stirring every 20 seconds, until smooth (about 90 seconds total). Spread it into the prepared pan. In a microwave-safe bowl, melt the white chocolate on high, stirring every 20 seconds, until smooth (about 60 seconds total). Drop small spoonfuls onto the bittersweet chocolate and, using a skewer, swirl the white chocolate through the dark. Let the chocolate set for 5 minutes. Sprinkle with the candy canes, then refrigerate until set, about 30 minutes. Break into pieces before serving.