For the centre:
Melt the gianduja and chocolate together in a microwave bowl using short bursts at low power. Once melted continue to heat to 55℃. Stir in the raisins and place the bowl in a deep roasting tin of cold water. Stir with a rubber spatula until the mix reaches 28℃. Pour into a clingfilm lined tray and allow to set. Immediately the mix is firm, coat both sides in a thin layer of untempered milk chocolate (this prevents the dipping fork sinking into the gianduja and the chocolates becoming stuck on the fork). Cut into 2.5 cm squares.
For the tempered chocolate using a Panasonic 1800 watt oven:
In a 1 litre pyrex bowl with 500g 60% cocoa solid chocolate pistolles
Heat on power 5 for 30 seconds and stir. Heat on power 5 for 30 seconds and stir. Once fully melted make sure the temperature reaches 55℃. Cool the chocolate over cold water to reach 27℃. Heat on power 5 for 5 second bursts to bring temperature to 31℃.
To finish:
Use the chocolate immediately to dip the gianduja squares. Before the chocolate solidifies, sprinkle on a little chopped roasted hazelnut.