Line a baking sheet with parchment paper.

Melt the semi-sweet chocolate in a microwave-safe bowl in 30-second intervals, stirring between each, until smooth. Spread evenly on the parchment paper in a thin layer. Let set for about 5 minutes — you want it starting to firm but not completely hard.

Melt the white chocolate the same way. If using peppermint extract, stir it in now. Pour over the dark chocolate layer and spread evenly.

While the white chocolate is still wet, sprinkle the crushed candy canes over the top and press them in gently.

Refrigerate for at least 30 minutes until completely set, then break into pieces. Clara and I make this every December and package it up for teacher gifts.