Using the wide holes of a box grater, shred the potatoes and onion onto a cheesecloth and squeeze out all of the excess liquid.
Place the shredded potatoes and onion in a large bowl and mix in two eggs with your hands.
Add the baking powder, salt, black pepper, and flour and mix just until incorporated with your hands.
Heat the canola oil in a large frying pan over medium heat. To check if the oil is hot enough, drop a little piece of batter in the oil. When it sizzles, it’s ready.
Use a medium scoop to portion each latke into the oil, and use the back of it to flatten them.
Cook for about 10 minutes per side, until deep golden brown.
Transfer from the pan with tongs or a fish spatula to a plate lined with a paper towel. Sprinkle with flaky salt immediately after removing from the pan.
Serve immediately and top with sour cream, chives, and everything but the bagel seasoning.
