Set up your food processor with the shredder attachment. Set up a bowl full of cold water and add a 1/4 teaspoon apple cider or white vinegar. Set up a big plate or baking sheet with paper towels to drain the oil.
Shred the potatoes and onion in the processor and dump it into the bowl of vinegar water. Let sit for 5 minutes.
Drain into a kitchen towel or cheesecloth and squeeze out as much water as you can.
To another big mixing bowl, add the aquafaba and whisk until just frothy. Dump in the potatoes. Add the flour, baking powder and salt and mix well. Let sit for 5 minutes. Mix again.
Heat a nonstick skillet over medium-high heat, add a good layer of oil. When it is super hot, scoop the mixture onto the pan, being careful not to burn yourself, three or four latkes at a time. Cook on the first side until golden brown, about 5 minutes. Use offset spatulas or other spatula to flip them over and cook on the second side until golden brown. Cook the latkes in batches and add more oil as needed.
Place the latkes on the paper towels to drain. Serve immediately or let cool and then serve a few hours later or refrigerate for a few days or freeze for a later date. Either way, cover and reheat in the oven until hot.