Line a 28 x 18cm baking tray with baking paper and put to one side.
Put the Hobnob biscuits in a food bag and crush with a rolling pin or with your hand. They don't have to be fine, or even. Just in rough pieces. Put aside.
Put a heatproof/ovenproof bowl over a saucepan of simmering water, making sure the bottom of the bowl isn't touching the water.
Put the chocolate, the butter, and golden syrup into the bowl and heat for 3-4 minutes, stirring, until the chocolate and the butter have melted and you have a lovely smooth mixture.
Take off the heat, then add the biscuits and raisins and mix until well combined. Transfer to the lined baking tray, smoothing the top with a spoon or knife so that it’s flat and even.
Taking the Mini eggs, place them into the chocolate biscuit mixture and press them in gently and spread them out evenly.
Set aside for 10 minutes to cool, then wrap with clingfilm. Refrigerate for 2 hours.
Break the white chocolate in pieces and put into a suitable container and melt in a microwave on a high heat for 2 minutes. When melted, drizzle over the fridge cake and then put it back in the fridge for another hour.
Once set, remove from the baking pan, then using a sharp knife, cut into slices. I like mine thick and chunky and with a nice cup of tea!