Coarsely grate the courgette using the larger side of a cheese grater, then weigh out 215g into a large bowl, do not squeeze it out.
215 g coarsely grated courgette (zucchini)
Stir in the yogurt, milk, oil, sugar, vanilla extract and vinegar.
80 g (⅓ cup) plain non-dairy yogurt (I use Greek style soya), 90 g (6 Tablespoons)) unsweetened non-dairy milk (I use soy), 110 g (½ cup) oil (I use olive), 160 g (¾ cup) light brown soft sugar, 2 teaspoons vanilla extract, 2 teaspoons vinegar (cider or white wine are best)
Stir in the cinnamon, nutmeg, allspice, baking powder, bicarbonate of soda and salt.
3 teaspoons ground cinnamon, ½ teaspoon ground nutmeg, ½ teaspoon ground allspice, 2 ½ teaspoons baking powder, ½ teaspoon bicarbonate of soda (baking soda), ¼ teaspoon fine table salt
Add the flour and stir until no dry patches remain, but be careful not to over-beat the batter. Fold in the walnuts and sultanas.
305 g (2 ½ cups) plain (all-purpose) flour, 85 g (¾ cup) roughly chopped walnuts, 85 g (½ cup) sultanas or raisins
Cover the bowl with a tea towel and let it rest for 15 minutes. Meanwhile, preheat the oven to 220°C/200°C fan/425°F/gas mark 7. Line two muffin tins with 8-9 cases, spreading them out across the tins so that there is a gap in between each one.
Divide the batter between the muffin cases, filling them all the way to the top. An ice cream scoop is handy for this.
Bake for 7 minutes then turn the oven down to 180°C/160°C fan/350°F/gas mark 4. Bake for a further 15 minutes, until a skewer inserted into the centre comes out clean.
Allow the muffins to cool in the tin for 5 minutes, then transfer them to a wire rack and leave to cool completely. Once cold store in an airtight container.