Break the chocolate into pieces and melt it in a bain-marie (i.e., a heatproof bowl over a pot of hot water). The steam will melt the chocolate; when using chocolate in dessert recipes, it is important not to get it mixed with water.

In a different bowl or cup, mix the gelatin sheets with cold water. Soak them for about 5 minutes until soft. Remove the sheets from water and squeeze them to remove excess water.

In a small saucepan, heat the whipping cream.

Add the gelatin sheets and stir until dissolved, without allowing the whipping cream to boil. Remove the saucepan from the heat.

Separate the egg white and egg yolk.

Whisk the egg white with the sugar.

Whisk the melted chocolate and the whipping cream.

Using a flexible spatula, incorporate the egg white foam and egg yolk into the chocolate.

For serving, you can pour the mousse into glasses. Before pouring the dessert, crush about half a piece of gingerbread for each glass.

Place the gingerbread on the bottom of the glass and add the mousse.

Refrigerate the dessert for about 5 hours.

Add the rest of the gingerbread on top. You can also add roasted or raw almond slivers and cinnamon.