Start by making a "eggnog" in a bowl, i.e., mix eggs and sugar and whisk it together until it foams.
In the meantime, melt the butter in either the microwave or a saucepan.
Mix all the remaining (dry) ingredients in another bowl and sift them into the egg mixture.
Whisk with an electric whisk and gradually add the milk.
When everything is well mixed, add the butter.
Stir well and the cake batter is now ready.
Pour everything into a pan (I used a square 30 cm x 30 cm) lined with parchment paper.
Make sure the cake batter is evenly distributed so it doesn't bake unevenly.
Bake it at 180 degrees Celsius (356 degrees Fahrenheit) fan oven. It took 35 minutes for me, but depending on your oven, it can easily take 5 minutes less or more.
Remove from the oven and let it sit on a rack to cool down.
To make everything fit together, start the icing when you take the cake out of the oven.
Put everything in a saucepan over medium heat.
It should just "boil" for 1 minute while stirring vigorously.
Turn off the heat and let it cool down a bit.
It should be ready by the time the cake has cooled, so pour the icing over.
Place it (preferably in a cool place) and let it cool for about 1 hour.
The cake definitely doesn't get worse if left until the next day.
Enjoy.
