Using a stand mixer fitted with the paddle attachment, cream together the butter and sugar until pale and smooth. Add the whole egg and extra yolk and mix until incorporated.
2
Step 2
Now add the cocoa powder, cricket powder and flour to the mixture, and mix on a low speed until evenly combined. Lastly add the chocolate chips and milk and mix briefly until incorporated.
3
Step 3
Tip the mixture onto a sheet of cling film and roll into a log, about 6cm in diameter. Wrap the log in the cling film, sealing the ends, and place in the fridge to set for several hours, preferably overnight.
4
Step 4
When ready to bake, preheat the oven to 180°C/Fan 160°C/Gas 4 and line a large baking tray with baking paper.
5
Step 5
Unwrap the log and slice into 16–18 discs, about 1cm thick. Place the dough rounds on the prepared tray, leaving a little space in between as they will spread a little. (You may need to bake the biscuits in batches, depending on the size of your tray.)
6
Step 6
Place the tray on the middle shelf of the oven and bake for 11 minutes. Transfer the biscuits to a wire rack to cool.