In a food processor, fine-grate the potatoes (don’t liquefy; leave some texture), and strain to eliminate excess liquid. Don’t overdo it; just let the water drain out.
Fine-grate the onions, and mix in a large bowl with the potatoes. (If you don’t have a food processor, you can grind the potatoes and onions in a meat grinder.)
Add the eggs, baking powder, ¾ cup corn oil (most of it cooks out), flour, salt, and pepper; mix well. Fold in the matzo meal, making sure that everything is very well blended.
Heat ½ cup corn oil in a deep skillet. Spoon the batter (use a large kitchen spoon) into the pan to create pancakes about 3½-inches in diameter. Fry on low heat for 3 to 4 minutes until the underside is a deep golden brown, turn, and fry another minute or two. Drain on a paper towel. Serve with applesauce and/or sour cream.