Whisk the Just Eggs or applesauce with the sugar in a large bowl, add in the sour cream and whisk to combine. Add the apple cider vinegar to the soy milk and stir, let sit for about 5 minutes until it starts to curdle. Pour into the egg-sugar-sour cream mixture and stir to incorporate.

Sift the baking soda or hornsalt (hartshorn) if using, baking powder, cardamom and flour into a separate bowl, then carefully fold in the dry mixture into the wet ingredients until you have a firm, slightly moist dough (you might have to use your hands here).

Cover the bowl, place in the refrigerator and let rest until the following day.

When ready to bake the doughnuts, remove the dough from the refrigerator, and transfer onto a clean, lightly floured work surface. Roll out the dough using a rolling pin to about ½ inch thickness. Using either a doughnut cutter or two cookie cutters (one 1 inch (2.5 cm) and the other 4 inch(10cm), cut out the doughnuts and place onto a sheet tray. Place in the fridge to keep the doughnuts cold while you heat up the oil.