Preheat the oven to 170 degrees Celsius (338 degrees Fahrenheit) conventional.

Cut butter into smaller pieces and place it in a mixing bowl with sugar. Whisk it well together for 2-3 minutes.

Then add the eggs one at a time, beating to get a homogeneous mixture.

Sift the flour, baking powder, and vanilla sugar into the butter mixture and mix well to a light and airy basic batter (similar to, for instance, a sponge cake base).

Squeeze the juice from a lemon and grate the zest (be careful not to include the white part, it's bitter). Add the lemon zest and juice to the batter and mix well.

Pour the batter into a springform pan with the bottom lined with baking paper (the springform should have a diameter of 10 centimeters, which is a fairly standard size).

Once the batter is in the springform, create a small dip in the middle of the batter using the back of a spoon. By making this small dip, you avoid the batter rising more in the middle of the cake and forming a peak when baked. Instead, the cake will have a nice, even surface that’s easy to decorate later.

Place the springform in the hot oven and bake the cake for about 45 minutes at 170 degrees Celsius (338 degrees Fahrenheit) conventional. Baking time may vary between ovens, so check the cake regularly to avoid ending up with a very dry cake.

When the cake is fully baked (in my oven, it takes 45 minutes), take it out and let it cool in the springform on a cooling rack for at least 30 minutes before releasing it from the pan.

Once the cake has cooled and is released from the springform, cut the cake into two parts. They will then get the classic moon shape we know.

Decorate your lemon moon with the classic yellow icing and a bit of wood sorrel.

It can also be decorated with melted white chocolate and some lemon zest:

Let your imagination run wild and enjoy summer with a fresh and delicious cake.