Make the caramel by melting together butter, sugar and condensed milk. Once it is melted, turn up the heat and let it bubble whilst stirring constantly for 6 minutes on a gas hob (or simmer for 10-12 minutes on an induction hob) . Pour the caramel on top of the biscuit base and put it in the fridge to cool and set. Next, pour melted Galaxy chocolate over the top and decorate with the Galaxy chocolates

HOW DO YOU CUT UP MILLIONAIRE’S SHORTBREAD?
To cut millionaire’s shortbread into neat slices, it is best to do this when it is at room temperature. If you do it straight from the fridge, the chocolate on top could crack, and will be quite solid so will press into the caramel and cause it to ooze out. At room temperature, and using a large sharp knife (ideally a knife that is bigger in length than the length of the shortbread), and gently cutting through works well for me.