Put the gelatin in cold water to soak.
Mix the sugar with the egg yolks.
Bring the milk to the boil.
Pour the mixture into the milk, stir continuously with a whisk and cook until it reaches a velvety, creamy density. Do not boil.
Squeeze out the gelatin and add to the hot mixture, stir.
Add the coffee and liqueur at this point.
Let the mixture cool down, but don’t allow it to solidify.
Whip the cream and add it to the cold mixture, folding it in from the bottom up.
Fill 6 one-portion molds or a large mold and place in the fridge for 6 hours.