For the cake:

250 g flour

1½ teaspoons of baking powder

250 g soft butter, softened

250 g extra fine powdered sugar

4 large eggs

Zest of 1 lemon  (untreated)

1 lemon cut into thin slices (optional)

For the syrup:

The juice of 1½ lemons freshly squeezed

100 g powdered sugar

For the icing:

100 g powdered sugar

 lemon juice

Prepare the cake:

Preheat the oven to 180°C. 

Line a cake pan with baking paper.

Sift the flour and baking powder into a bowl.

Mix the butter and sugar with an electric mixer(fast speed) in a bowl until you have a light and creamy mixture.

Add the eggs one by one without stopping stirring until well blended.

While reducing the speed of the mixer, add gradually the flour mixture and lemon zest.

Using a spoon, spread the batter into the pan and level the surface.

Bake for 45-50 minutes, until the cake is golden brown. 

Make the syrup:

quickly mix the lemon juice and sugar in a bowl.

Prick the top of the warm cake with a toothpick or a fork, Top with the lemon cut into thin slices.

Gently pour the syrup over the top, so that the juice is absorbed but the sugar remains on the surface and forms a delicious, crisp topping.

Let cool in the pan on a wire rack.

Make the glaze: 

Mix together the lemon juice and sugar, adding a little hot water if necessary, the glaze should be quite thick. Arrange the glaze on the cooled cake.

When preparing the syrup, be sure to stir the sugar only when it is dissolved in the lemon juice. 

the syrup should be a little grainy this gives a nice texture to the surface of the cake.