Step 1
Line the base and sides of a standard loaf tin (about 20cm x 10cm) with baking paper, making sure there are a few centimetres overhang on the longer sides.
Step 2
Preheat the oven to 165C fan-forced (185C conventional).
Step 3
Sift the flour, cocoa powder, baking powder, bicarb soda and salt in a medium bowl, then add the ground almonds. Set aside.
Step 4
Combine the eggs, brown sugar, oil, yoghurt and vanilla extract in a large bowl and whisk for about a minute until creamy and fully blended. Add the grated zucchini and mix to combine, then add in the sifted, dry ingredients. Using a flexible spatula, fold gently and, when almost combined, add 100g of the chopped chocolate and 50g of the chopped hazelnuts. Fold until just combined, then scrape the batter into the prepared loaf tin.
Step 5
Scatter the remaining 50g of dark chocolate and 50g of hazelnuts evenly on top of the cake, then place in the oven. Bake for 1 hour and 15 minutes (if the nuts are browning too quickly on top, cover the cake loosely with kitchen foil) or until a skewer inserted into the middle of the cake comes out clean.
Step 6
Cool the cake in the tin on a wire rack for a few minutes before lifting it out of the tin to cool completely. Slice thickly to serve.
