I also sometimes make this biscuit base and instead of adding the dark chocolate I add macadamias and sultanas, they are as good as the chocolate version. I whizz these up in my kitchenaid and they are super quick, the boys eat them warm before they even get a chance to crunch up but not me, no siree, I wait for the crunch.
125g plain flour
1/2 tsp salt
1/2 tsp bicarbonate soda
115g dark chocolate chips
110g softened unsalted butter
1/3 cup caster sugar
1/3 cup raw sugar
You'll want the oven at 175, but the biscuits go in the fridge for a while so don't it now. Cream the sugars and butter till pale and fluffy. Add egg, combine. Sift over flour, salt and soda, drop in chocolate chips and mix till combined, finito.
Lay out 2 sheets of clingwrap and put half the mixture in the middle of each one in a log shape, wrap and roll til smooth and about 4cm in diameter, pop into the fridge for an hour.
Remove from fridge, unwrap and slice into 1.5 cm thick slices. Place on lined baking tray and cook for 12 minutes allowing room to spread a bit. Cool on wire rack.