Using a hand grater or food processor, grate the potatoes. In a mixing bowl, combine the grated potatoes, onions, eggs, baking powder, and flour. Mix well. Season with salt and pepper.
In a large skillet, over medium−high heat, cover the bottom with 1/2−inch of oil. When the oil is hot, spoon 2 tablespoons of the filling into individual cakes. Using the back of the spoon, flatten each pancake.
Pan−fry until golden brown on each side, about 2 to 3 minutes. Remove from the oil and drain on paper towels. Fry the cakes in batches and do not over crowd the pan.
To serve, place a dollop of the applesauce or sour cream in the center of each latke.
Place the latkes on a platter and serve warm. Yield: 2 dozen