Prep the potatoes. First things first, peel all of the potatoes (or recruit a handy assistant to do it for you).
Grate potatoes and onion: By hand or with a food processor, grate the potatoes and onion
Dry the potatoes and onion: This is the most crucial step! To make crispy latkes, the grated potatoes and onions must be super dry. I spread them over a hand towel to absorb the moisture and then roll them up to squeeze out the rest.
Mix latke batter: In a large mixing bowl, add the dried potatoes and onions, eggs, flour, salt, and pepper (do not be shy with the seasonings -latkes need a lot of salt and pepper). Mix the ingredients until the mixture is just combined. You want it to have texture, but it shouldn't clump together.
Using about a 1/4 cup of batter per patty, mold the mixture into about 4" rounds.
Heat oil: In a cast-iron or large heavy-bottomed no-stick skillet, add oil filling the pan about 3/4" high and heat over medium to medium-high heat until hot but not smoking. Make sure the oil is hot enough (ideally between 360 and 375 degrees F). Otherwise, you will end up with a wet and soggy latke.
Cook: Pan fry potato pancakes until they are browned and crispy on both sides. Please do your best only to flip them over once.
Strain: Transfer crispy latkes straight from the hot cooking oil to a paper towel-lined pan. I like to let them soak in layers divided by paper towels.
Serve: If needed, sprinkle with a bit more salt to taste. Serve with sour cream and apple sauce. Enjoy!