½ orange, finely grated zest only
¼ tsp bicarbonate of soda
80g/2¾oz caster sugar
65g/2â…“oz caster sugar
15g/½oz cocoa powder
15g/½oz icing sugar
pinch fine sea salt
100g/3oz self-raising flour
30ml/1fl oz sunflower oil, plus extra for greasing
½ tsp vanilla extract
½ tsp vinegar, any variety
50ml/2fl oz aquafaba, shop-bought or from a tin of organic chickpeas