Preheat the oven to 180°c/Gas Mark 4, Rack in the middle.
Mix the Flour and baking powder, if not using self raising, together and sift twice to mix well. Set aside.
Mix the butter with the lemon zest using a wooden spoon or mixer until creamy.
Add the sugar, continue to mix until extra creamy.
Now add one egg at a time continuing to whisk. Add a spoonful of the flour with each egg to stop the eggs curdling.
Fold in the remaining flour using a spoon and add some of the lemon juice (approximately 2 tbsp, but to taste)
Line a loaf tin with greased parchment and spoon in the mixture ensuring it is evenly spread out.
Put into the over for 50 minutes, or until it is cooked through. Test with a knife inserted to the middle. if it comes out clean it is ready. Do not open the door of the oven until at least half way through cooking or you'll have a very flat cake.
Remove from the oven and tin, place on a cooling rack until completely cooled.
Mix the Icing sugar and lemon juice to create a runny but not water like consistency and pour over the cake. It's ok to be messy...
Add sprigs of your favorite flower to decorate the cake. I like sage as it goes very well with lemon and actually adds flavour rather than just being pretty.
Serve your showstopper cake to your friends and delight in the little wild addition!