1: Preheat the oven to 360°F (180°C). Put into a food-mixer bowl: 125 g butter cut into small pieces, 125 g caster sugar, 10 g vanilla sugar, 50 g flour, 100 g ground almonds, 3 tablespoons rum and 2 pinches salt. Start mixing on slow speed.
2: Break 3 eggs into a jug or bowl and beat briefly with a fork.
3: Add the eggs to the mixture.
4: Continue beating until evenly mixed.
5: Spread the mixture in a non-stick cake tin or mould.
6: Bake for 30 or 40 minutes.
7: Turn out while hot and leave to cool on a wire rack
8: Prepare the icing by mixing 100 g icing sugar with about 1 tablespoon rum (you may well need to vary the amount of rum). Pour the icing on top of the cake.