Grate the potatoes using a coarse grater and thoroughly squeeze out the excess liquid. (Some recipes even suggest rinsing the potatoes with cold water before squeezing; we tried it and liked the result.) Finely chop the onion.
Combine the grated potatoes, chopped onion, eggs, flour, salt, black pepper, and baking powder in a bowl. The mixture should be smooth and fairly thick, with no lumps.
Heat vegetable oil in a heavy-bottomed pan. To check the temperature, drop a cube of bread into the oil—it should turn golden within 15-20 seconds. This will help prevent the latkes from absorbing too much oil.
Spoon the latke mixture into the hot oil and fry until golden on both sides. Remove from the oil and place on paper towels to absorb any excess oil.
Serve warm with various sauces. Sauce recipes can be found in the following recipe.