Grease a line a 20 x 30cm (8 x 12") slice tin, leaving extra parchment overhanging to help you remove the slice from the tin, and set aside.
Crush biscuits into a fine crumb using a food processor (or place them in a plastic bag and give them a bash with a rolling pin), and place into a bowl.
250 g plain sweet biscuits
Then add condensed milk, melted butter, lemon juice & zest, roughly chopped dried blueberries and desiccated coconut to the biscuit crumbs and mix well to combine.
250 g condensed milk, 80 g butter, 70 g dried blueberries , zest and juice of 1 lemon, 45 g desiccated coconut
Press mixture into the lined tin and even out the surface, then set aside.
Place the white chocolate and vegetable oil in a small microwave-safe bowl and melt in the microwave in 30 second bursts (mixing with a metal spoon in between bursts) until just melted, then mix well to combine the oil and chocolate.
225 g white chocolate , 2 tablespoon vegetable oil
Pour the melted white chocolate on top of the lemon biscuit base, tilting to spread evenly. Sprinkle extra coconut on top and place in the fridge for 1-2 hours, or until set.
1-2 tablespoon extra coconut for sprinkling