Heat oven to 180C/160C fan/gas 4.
Line the base of a 21cm square tin with
baking parchment. Put the cocoa, butter
and sugar in your largest saucepan and
gently melt, stirring so the mixture doesn’t
catch. When the cocoa mixture is melted
and combined, cool slightly, then stir in
the eggs, little by little, followed by the
flour and coconut.
Tip into the tin and bake for 45 mins
on a middle shelf – check after 30 mins
and cover with another piece of baking
parchment if the crust is browning too
much. Cool in the tin, then carefully lift
out and cut into squares.