Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Grease the hollows of a ring cake tin (for 24 pieces) and dust with flour. Cream 75 g butter, sugar, orange peel and 1 pinch of salt with the whisks of the mixer.
Stir in the eggs one by one. Mix chia seeds, 125 g flour and baking powder. Stir the quark and 1 tbsp. orange juice briefly into the butter-sugar cream. Pour the dough into a piping bag.
Fill hollows to about 2⁄3 with about half of the dough. Bake in the hot oven on the lower shelf for about 10 minutes. Take out and let cool down for about 5 minutes. Turn out carefully and let cool down.
Wash and dry the baking tray, grease it again and dust it with flour. Bake the rest of the dough as described under point 2.
Stir icing sugar with 1-2 tablespoons orange juice until smooth. Drizzle the ring cake with icing. Decorate with fruits as desired. Let the icing dry.