Scrub baking potatoes; do not peel. Shred potatoes and onion in a food processor; drain, pressing between paper towels.
Place potatoes and onion in a large bowl; stir in eggs and next 3 ingredients until combined.
Pour oil to a depth of 1/2 inch in a large heavy skillet over medium-high heat; heat oil to 350°. Squeeze about 1/4 cup potato mixture firmly in hand to remove excess liquid; carefully drop into hot oil. Fry, in batches, 3 to 4 minutes on each side or until golden. Drain on paper towels. Place drained latkes on a wire rack on an aluminum foil-lined baking sheet. Keep warm in a 200° oven up to 30 minutes. Serve with applesauce.