Preheat the oven to 425 and spray a 12-cup muffin tin.  Stir together the grated zucchini and salt in a medium bowl, toss the blackberries together with the sugar in a separate bowl and leave both bowls to sit for about 10 minutes while you measure out the remaining ingredients.

In a large bowl, whisk together the olive oil, brown sugar, eggs, yogurt, molasses and vanilla until smooth.  Squeeze out the zucchini if needed and then stir it all into the wet mix.  Next whisk in the baking powder, baking soda, nutmeg and salt, then add in the flour and fold until just combined.

Spoon a couple of tablespoons of batter into the bottom of each greased muffin cup, tap the pan a few times, drop in 3 to 4 pieces of blackberry, evenly top with the remaining batter, followed by the remaining blackberries, then a generous sprinkling of more coarse sugar.

Bake for about 15 minutes until the tops bounce back to a light touch and the muffins are a deep golden brown.  Leave them to set in the pan for about 10 minutes before turning out onto a rack to cool – the berries may cause a few to stick a bit, but an imperfect muffin simply needs to be eaten first!