Pre-heat oven to 170 degrees celsius, fan-forced (or equivalent).
Grease a slice tin (approx 28 x 18cm) and line with baking paper, leaving paper overhanging at sides to assist with removal from tin later.
Line bottom of tin with saladas – they may double up in parts.
Combine sugar and butter in a saucepan over low heat, stirring until butter melts and sugar dissolves. Bring to a simmer, turning up heat if necessary, and simmer for 1 minute without stirring.
Pour over saladas and spread to edges with a spoon if necessary to ensure saladas are completely covered.
Cook for 5 minutes or until caramel starts to bubble.
Remove from oven and melt milk/dark chocolate by placing in microwave for 25 second bursts and stirring between each burst until completely melted. Pour melted milk/dark chocolate over the caramel layer.
Melt the white chocolate by placing in microwave for 25 second bursts and stirring between each burst until completely melted. Drizzle lines of white chocolate over the milk/dark chocolate layer.
Decorate with silver cachous, red and green sprinkles, edible glitter.
Allow to cool a little and then place in the fridge to set completely.
Once set, cut into shards using a sharp knife. Or "crack" it into pieces with your hands!
Store Christmas Crack in an airtight container in the fridge for up to one week.