For food safety, you may substitute the raw egg yolk with pasteurized egg yolks or omit it entirely for a simpler, though slightly less rich, cream.
Ensure the coffee is cooled to room temperature before dipping the biscuits to prevent them from becoming too soggy too quickly.
This dessert improves in flavor after resting overnight in the refrigerator.
Store covered in the refrigerator for up to 3 days.