Butter a 2-litre baking dish and heat
oven to 180C/160C fan/gas 4. Put the
kettle on. Put the flour, caster sugar,
50g cocoa, baking powder, orange zest
and a pinch of salt in a large mixing bowl.
Whisk together the orange juice and any
pulp left in the juicer, the eggs, melted
butter and milk, then pour onto the dry
ingredients and mix together until
smooth. Stir in the chocolate chunks and
scrape everything into the baking dish.