Grease a pancake tin (2 l capacity) and dust with flour. Clean and wash the spinach, drain well and chop coarsely. Finely puree the spinach and oil with a hand blender. Wash and dry organic lemon hot, rub off the peel.
Squeeze the lemon. Stir the juice and zest of the organic lemon into the spinach. Chop the chocolate and melt in a hot water bath.
Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Cream eggs, sugar and vanilla sugar with the whisks of the mixer. Mix flour and baking powder. Add the spinach puree and flour mixture alternately to the egg mixture and mix to a smooth dough.
Fold in the melted chocolate.
Put the dough into the mould and smooth it down. Bake in a hot oven for about 1 hour. Approx. 10 minutes before the end of the baking time check with a long wooden skewer whether the cake is ready. If there is still soft dough sticking to the skewer, continue baking for 5-10 minutes.
Take out the cake and let it rest in the mould for about 10 minutes, then turn onto a cake rack and let it cool down.
Sieve the icing sugar into a bowl. Stir in 4-5 tablespoons of lemon juice with the whisks of the mixer to make a smooth, thick glaze. Spread the icing unevenly over the cake and decorate with flowers.
Allow to dry.