Preheat oven (electric cooker: 180 °C/circulating air: 160 °C/gas: see manufacturer). Grease a fat pan (deep baking tray; approx. 32 x 39 cm) and dust with flour. Wash organic lemons hot and dab dry. Finely grate the peel. Squeeze all lemons (if necessary, fill up to a total of 250 ml with water).
Mix 500 g soft butter, sugar and 1 pinch of salt with the whisk of the mixer for about 10 minutes until light creamy. Stir in the eggs one after the other.
Mix 400 g flour with starch. Alternate with lemon juice, except for 5 tbsp. for the icing, stir in briefly. Smooth the dough on the tray. Bake in a hot oven for about 25 minutes.
Defrost raspberries at room temperature. Remove the cake from the oven and let it cool down.
For the icing, stir icing sugar with the remaining lemon juice until smooth. Mix the grated coconut and thawed berries with the whisk of the mixer in a narrow mixing bowl. Spread the icing on the cake and sprinkle with coconut flakes.