1.  Ensure the frozen berries are defrosted at least 1 hour in advance, and set aside in a strainer to drain the juices from the berries.

2. Preheat oven to 180°c Fan.  Grease and line a 20cm x 20cm square baking tin with parchment paper.

3. In a large wide mixing bowl rub the shortbread ingredients together using your fingertips until they resemble breadcrumbs (or mix together in a food processor).

4. Press the dough into the lined tin using your fingertips, then use the back of a spoon to give a smooth level surface. Bake in the preheated oven for 20 minutes or until the top is golden brown.  Remove from the oven and set aside.

5. In a large mixing bowl, use an electric whisk to beat the eggs and sugar together until pale and fluffy.  Add in the vanilla extract and lemon zest.

6. Sieve together the flour and baking powder and fold into the batter.  Gently fold the drained berries and coconut through the mixture until just combined.

7. Pour the fruit mixture over the prebaked shortbread.  Bake on the middle shelf of the preheated oven for 45 minutes to 1 hour until golden on top.  Allow to cool fully in the tin, dust with a little extra icing sugar or coconut before cutting into slices.