Place the biscuits into a food processor and process until they are a fine crumb. Add the chopped apricots and condensed milk.
Meanwhile, heat the butter and sugar in a small saucepan until the butter has melted and the sugar has disolved. Add to the biscuit mixture and stir until well combined.
Press into the lined tray, and place in the fridge for 2 hours or until firm.
Melt the white cholocate and spread over the top of the slice. Add drops of the orangefood colouring, and use a skewer to swirl to make a marble effect.
Place in the fridge to set overnight then cut into slices.