Mix the butter and sugar together with
a wooden spoon. Stir in the flour and
cocoa, followed by the chocolate chips
– you’ll probably need to mix it together
with your hands at this stage. Halve the
dough and roll each piece into a log
about 5cm thick. Wrap in cling film and
chill for 1 hr or for several days. Can be
frozen for up to 1 month.
Heat oven to 180C/160C fan/gas 4.
Slice logs into 1cm-thick rounds, transfer
to a baking tray lined with baking
parchment and bake for 10-12 mins.
Cool on the tray.