Heat the oven to 180C/160C fan/gas 4.
In a large bowl, combine the flour, cocoa
powder, mixed spice and 1 tsp salt. In
another bowl, combine the olive oil,
sugar, eggs, vanilla essence and grated
courgette. Mix the dry and wet mixture
until just combined, then fold in the
toasted hazelnuts. Line a 24cm cake
tin with greaseproof paper, then pour in
your mixture. Bake for about 40-50 mins,
or until a knife inserted into the middle
comes out clean. Cool in the tin for
10 mins, then turn out onto a wire
rack and leave to cool.