Whisk together the sugar, salt, vanilla sugar, and eggs until white and fluffy (this takes about 8-10 minutes).

Sift all the flour into the egg mixture and gently fold it in.

Mix the oil and milk in a bowl and stir a small amount of the batter into it before gently folding it into the rest of the batter.

Distribute the batter in a cube form and bake in a preheated oven at 180 degrees Celsius (356 degrees Fahrenheit) ordinary oven for about 25 minutes.

Let the cakes cool on a wire rack.