1. Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).
2. In a bowl, combine sugar, eggs, oil, lemon juice and zest, and potato flour and mix well until smooth.
3. Thinly slice the peeled apples (or grate using a coarse grater) and add to the batter. Add nuts and cinnamon and mix well. Season to taste if necessary.
4. Line an eight- by eight-inch baking pan or two loaf pans with Gefen Parchment Paper and pour in the batter.
5. Bake for 45 minutes, until golden brown.