First, make the honeycomb. Have a wire whisk and an oiled baking tray set out on the side. Put the sugar and golden syrup into a saucepan and put on a very low heat. Warm gently for 10 minutes, until all of the sugar has dissolved, stirring occasionally with a wooden spoon.
Once the sugar has completely melted, turn up the heat to medium. Once the mixture has started to boil, leave to bubble without stirring until it turns golden-brown. Turn off the heat under the pan. Cover one of your hands with a dry tea towel or oven glove for protection, then take hold of the pan handle. Add the bicarbonate of soda and quickly whisk in for a couple of seconds only. The mixture will froth vigorously and you need to take great care as it's extremely hot.
Quickly pour the mixture into the middle of the oiled baking tray. Don't spread it out or touch. Sprinkle on the raisins and leave it to cool. This should take about 30 minutes.
Next, chop the Double Decker into small pieces and melt in a bain-marie with a teaspoon of butter. Once the mixture has melted, use a wooden spoon to smooth and spread across the honeycomb in the tray.
Next, melt your Dairy Milk bar in a bain-marie. When the chocolate is smooth and shiny, pour onto the honeycomb and, using a palette knife or the back of a spoon, smooth over your honeycomb and leave to set.
Once set, eat as it is or with some ice cream. I'll be having it with some Ben & Jerry's.