Make the Sponge:
Beat the eggs, salt and sugar on your kitchenmashine with the whisk for 5 min, in the meantime turn on the oven at 170 degrees. But the flour and vanilla in a bowl and fold it slowly into your egg mix. Pour the mixture in a square oven tray wich is lined with baking paper.
Bake for 25 min, then let it cool.
Brew 300ml strong black coffe, add the rum, st aside to cool completely
Milk, cream and sugar bring to the boil seperate the eggs and but the yolks in a big bowl. Add the hot milk to the yolks and whisk very well, then let it cool down complete for about 5h in the fridge. But the butter in the kitchenmashine and let it cream up at medium speed, after 10 min scrap down the side and beat again, till light and fluffy. Now add slowly the cool egg mixture slowly till everything is beaten in the butter cream. Now add the egg nog and the rum.
Cut the sponge in thin layers 3 times and now drizzle a lot of the coffe mixture over the sponge, then fill the cake with the butter cream, add sponge again and drizzle the coffe rum over the cake again, add butter cream and repeat so on. After spread the cream all over the cake to seal the cake well.
Now but it in the fridge and let it sit there for 1 or 2 days.
Before serving cover the top of the cake with thick whipped cream and drizzle chocolate sauce and egg nog all over the cake.
Hmmmm yummy..... enjoy!!