Triple Chocolate Peppermint Bark

With a pencil and ruler, mark a 13×9-inch rectangle on a piece of parchment paper large enough to fit in a rimmed baking sheet. Flip the paper over (so the pencil marks are on the bottom) and place the paper in the baking sheet.

Place bittersweet chocolate in a heatproof bowl; set bowl over a saucepan of barely simmering water. (Do not allow the bowl's bottom to touch the water.) Stir occasionally until chocolate is melted and smooth. Pour melted chocolate into the rectangle marked on parchment. Using an offset spatula, spread chocolate to fill rectangle. Chill until set, about 15 minutes.

Meanwhile, in the same bowl, combine semisweet chocolate, cream and peppermint extract. Set bowl over the barely simmering water until chocolate is just melted and smooth, stirring frequently. Remove bowl from heat and let cool until room temperature, about 15 minutes. Pour semisweet chocolate mixture over chilled chocolate rectangle. Using an offset spatula, spread evenly over top. Chill until very firm, about 1 hour.

In a clean bowl, warm white chocolate over barely simmering water until melted and smooth. Working quickly, pour white chocolate over the firm semisweet layer, using a clean offset spatula to spread it evenly. Sprinkle with crushed candy canes. Chill just until firm, about 20 minutes.

Carefully transfer parchment paper with chocolate from the baking sheet to a cutting board. Cut or break bark into squares, triangles or bars, as desired. If cutting, let the bark sit out a few minutes to slightly soften for cleaner cuts.

Let bark stand at room temperature 10 minutes before serving. Store in an airtight container layered between sheets of wax paper or parchment paper up to 1 week.