Halve the lemon and squeeze it. Put lemon juice, 1/8 l water, 5 tablespoons sugar and vanilla sugar in a pot. Peel, quarter, core and cut apples into small cubes.
Boil apples in lemon water. Cover and cook for 15-20 minutes until the apples are mushy. Mash them even more finely with a potato masher and sweeten if necessary.
Peel onion and potatoes. Wash the potatoes. Grate potatoes finely in a bowl. Add the onion. Add eggs, flour and about 1/2 teaspoon salt and mix well.
Heat 1 tbsp. clarified butter in a large pan and fry approx. 3 potato pancakes at the same time. For this purpose, put 2-3 tbsp. potato mixture per potato fritter in the pan and flatten it with a tablespoon.
Fry over medium heat - so that they do not burn - for about 3 minutes until the underside is golden yellow. Turn and bake for another 3-4 minutes. Bake 9 more pieces from the remaining potato mixture and lard.
Warm the finished potato pancakes in a hot oven (approx. 50°C). Sprinkle each potato pancake with sugar and serve with apple sauce. If you like, you can also eat them with sugar beet syrup on brown bread.