Put all the dry ingredients, including fruit and nuts, into a mixing bowl .
Add the oil and as much milk as you need to make a thick cookie dough (half a cup max) then stirring to combine everything. Make sure you can't see any dry bits of flour and you scrape the bottom of the bowl well.
Drop mixture onto the cookie sheet. I use an ice-cream scoop. Leave plenty of room round each one.
Flatten the tops of each cookie with the back of a fork.
Bake for 15-17 minutes. When ready they will be hardening up round the edges but slightly soft on the inside when you press with your finger. They will continue to firm up when you remove them from the oven.
Leave to cool on the tray.
When completely cool prepare the frosting.
Add the aquafaba to a small bowl and whisk until just starting to go thicker and foamy. I used an hand whisk. It's difficult as there is such a small amount but just tip the bowl slightly to the side. With an electric hand whisk it will take 30 seconds tops. By hand slightly longer.
Add the powdered sugar and vanilla. Stir with a spoon a little bit so it's not so dusty then whisk again for about two minutes until very thick.
Use a piping bag and a nozzle with a very small opening to pipe cross shapes across the top of each cookie.The crosses will dry hard within a few minutes.
If you don't happen to have aquafaba for the frosting then you can use water instead. You won't need to whip it up like the aqufaba. Just add the vanilla to the powdered sugar then add the water a drop at a time, stirring well until you have a thickish paste. If you can use aquafaba then please do as the crosses are much hardier with it.