Heat the oven to 180C/160C fan/gas 4 and line two large baking sheets with baking parchment. Whisk the sugar with the oil, aquafaba, milk, vanilla and lemon and orange zests. Mix the flour and baking powder with the salt in a separate bowl. Stir the dry ingredients into the wet, then add the nuts and dried fruit.

Halve the dough and shape each piece into a log about 20cm long x 4cm wide. Flatten slightly and bake for 30 mins until golden brown. Remove from the oven and leave to cool for 10 mins. The loaves will be delicate, so use a serrated knife to carefully cut them into 1cm-thick slices on the diagonal. Arrange on the baking sheets and bake for a further 10 mins. Flip the biscotti over and bake for another 10-15 mins until pale golden. Leave to cool on wire racks. Will keep in an airtight container for one week.