1. Lightly whip the cream - it should not be stiff.
2. Lightly heat the whiskey, but do not let it boil.
3. Stir in the brown sugar, stirring until dissolved, and pour into heat-resistant glasses.
4. Fill the glasses just over half-full with hot coffee.
5. Slowly add the lightly whipped cream by pouring it over the back of a spoon.
6. Decorate the glasses with a sugared rim if you wish.
7. To do this, whisk 1 egg white and put it on a shallow plate.
8. Put a little sugar on another plate.
9. Dip the rim of each glass first in the egg white and then in the sugar.