Heat oven to 180C/160C fan/gas 4.
Butter a deep, 20cm round cake tin
and line the base and sides with baking
parchment. Put the whole hazelnuts, plus
1 tbsp each of the sugar and flour, into
a food processor and whizz until the
hazelnuts are as fine as you can get them.
Add the butter, remaining sugar and
eggs to the processor, then tip in the
vanilla, spice, ¼ tsp salt, remaining flour
and baking powder. Whizz until smooth.
Remove the blade, then stir in the grated
courgettes, apple and dried fruit.
Spoon the mix into the tin, smooth
the top, then scatter with the chopped
hazelnuts, pressing them into the batter
a little. Bake for 1 hr 10 mins (see tip,
below), covering the top loosely with foil
after 45 mins, until the cake is risen and
golden. Cool in the tin for 20 mins, then
remove and cool on a wire rack.