Basic Butter Cake Batter

Take all ingredients out of the refrigerator in good time so they reach the same temperature.

Preheat the oven to 175 °C (fan/forced air).

Grease the cake pan with butter and dust with breadcrumbs or cake crumbs.

Separate the eggs: put the yolks in one bowl and the whites in a clean, fat-free mixing bowl.

Beat the egg whites with 75 g sugar until stiff peaks form.

Beat the softened butter with the remaining sugar, vanilla sugar, and a pinch of salt until very creamy and most of the sugar has dissolved.

Alternately add the yolks, flour, and rum to the butter–sugar mixture and briefly but thoroughly mix in.

Gently fold the stiff egg whites in 2–3 portions.

Pour the batter into the prepared pan and smooth the surface.

Bake in the preheated oven for about 50–60 minutes.

After baking, let the cake rest in the turned-off oven for another 10 minutes, then remove.