18-oz. white chocolate, melted
6-oz. crushed candy canes
6-oz. bittersweet chocolate, finely chopped
3-oz. heavy cream
3/4 tsp. peppermint extract
Spread half of the white chocolate into 12x8" rectangle on wax paper (on cookie sheet). Chill until firm.
While the white chocolate is chilling, melt the bittersweet chocolate wtih the cream and peppermint extract. Stir the mixture until well blended, let it cool to room temperate, then spread it on the chilled white chocolate. Chill to set.
Spread remaining white chocolate over the set bittersweet chocolate mixture, then top with the crushed candy canes. Chill to set, then cut into desired squares.