Ingredients for about 8 people

• 12 ounces self-rising flour (~2 cups — see instructions below)
• 2 eggs, separated
• 3 ounces butter
• 2 tablespoons sugar
• 1 tablespoon vanilla sugar
• salt
• 2.25 cups sparkling water
• 1 glug vegetable oil
• ⅓ cup powdered sugar

Preparation

1. If your store does not carry self-rising flour, make it by following this ratio: For every cup of all-purpose flour, add ½ teaspoon of salt and 1½ teaspoons of baking powder.
2. Cream the butter with the sugar until soft. Add the vanilla sugar, salt and the egg yolk and incorporate.
3. Pour the sparkling water into the flour and mix together then add to the butter mixture. (You can refrigerate the batter overnight at this stage.)
4. Beat the egg white stiff and add it to the mixture along with a glug of oil and fold it all in carefully.
5. Let the batter rest a while (it will rise a little). You can also rest it overnight at this point.