Line a square tin (24cm x 5cm, 9" x 2") with baking/parchment paper, leaving a 1-2cm overhang on all 4 sides (Note 5)
Use your hands to break candy canes in half, then add them to the bowl of the food processor. Blitz the candy canes for 15 to 20 seconds to crush into pieces. (Note 4)
Add sweetened condensed milk, chocolate and butter to a large heatproof jug
Microwave ingredients on high for 2 mins, then remove from microwave, place on heatproof surface and stir to combine. Return jug to microwave and microwave on high for an additional 1 min. Remove from microwave and stir for 1 minute till combined. (Note 6)
Reserve 1-2 tablespoons of the candy cane pieces for decorating. Then add blitzed candy cane pieces to the wet fudge and stir till they are covered and thoroughly mixed into the fudge
Transfer wet fudge into lined cake tin, sprinkle with reserved candy cane pieces to decorate and place in the fridge to set.
After 1 hour (or overnight), remove and use a sharp hot knife to cut into pieces (Note 7)