Mix the egg yolks with sugar and vanilla sugar / extract until foamy, stir in cream, coffee powder / espresso and starch (if powdered coffee is used, 1 teaspoon full, if liquid coffee is 2 teaspoons full), whip in a hot water bath for about 10-15 minutes until foamy until the mixture becomes thick, let it cool in a cold water bath, then stir in the brandy.
When the foam has set a little, fill it into a cleanly rinsed bottle, keep it cool, don`t wait too long to enjoy! It is estimated that it can be kept refrigerated for four weeks if it is not empty beforehand.