A new trend in the pastry world is the popularity of mousse cakes. You see them in coffee shops, pastry shops, elaborate buffets and ala carte desserts. 
The difference between mousse and mousse cakes is that the later is de-moulded out of the mould and garnished accordingly and retains its shape. 
Technically, mousses are not exactly new — they are presented in a better and modern way nowadays by pastry chefs. The creation of this classic dish is credited to French chefs who have been incorporating air in food and aerating their desserts with various ingredients since the 1700s and have always been committed to enhancing the overall food items being consumed. 
Mousse is prepared beforehand with a light and fluffy texture and the flavours may vary greatly depending on the choice and the availability of raw ingredients. 
A mousse can be sweet or savoury. Typically though the term mousse is associated with the sweeter version. The dessert mousse may or may not contain eggs, but most likely contains whipped cream, flavouring like chocolate, strawberry, coffee, caramel, fruit purses and sugar for sweetness and herbs and spices for masking them taste better. Sweetened mousse is served as a dessert or used as an airy cake with a filling. 
 The word “mousse” in French means foam and was recorded in the 18th century by a French culinarian and writer. The French have been experimenting with chocolate and have consistently improved on the existing recipes. 
The first written record of chocolate mousse in the United States comes from a Food Exposition held at Madison Square Garden in New York City in 1892. A “Housekeeper’s Column” in the Boston Daily Globe of 1897 published one of the first recipes for chocolate mousse. The recipe yielded a chocolate pudding-type dish, instead of today’s stiff, but fluffy, mousse.
Mousse became as we know it with the introduction of egg whites, separated from the yolks. The introduction of electric mixers made the foaming process much, much easier. Whipping egg whites by hand is not as effective or efficient method to get the work done. Everyone seems to have their own ideas when it comes to adding flavourings and even toppings, but the main ingredients in a chocolate mousse rarely change: chocolate, egg whites, and sugar. Some recipes also call for cream, butter and/or egg yolks. While some of us extreme-chocolatiers prefer the taste of the chocolate shining through the mousse, the addition of some flavours is also absolutely acceptable and turns the humble chocolate mousse to divine desserts.
As with any recipe that calls for chocolate, the secret is using the very best chocolate you can. Your mousse is only as good as your chocolate. This basic French chocolate mousse recipe is delectable in its simplicity. This is the ultimate splurge dessert! It’s very easy and quick to put together but shows off like something you’ve been working on all day. However, it does need a few hours in the freezer, so plan ahead and try out this recipe and prepare a mousse cake for your near and dear ones. Also, I have used real gold leaf in the accompanying picture to elevate the dessert to another level and make it special.


Note: To make the vegetarian version of mousse cake, remove egg from the recipe and add vegetable gelato to stabilise it.


Chocolate Mousse Cake


Ingredients
Dark chocolate chips 180 gms
Butter 1 tsp
Castor sugar 1 tbsp
Eggs 4 no
Whipping cream 1 cup


Garnish
Gold leaf to garnish


Method
Grease a pan with soft butter and sprinkle sugar and swirl to coat evenly.
Line the sides of pan with ladyfingers. 
Melt chocolate on double boiler to avoid burning the chocolate, stirring it continuously to avoid lumps, till it is smooth.
Transfer to a large mixing bowl and add yolks one at a time.
In a separate bowl whisk egg whites till soft peak.
Gradually add sugar and continue beating till the sugar is dissolved.
In a third bowl, whisk heavy cream till stiff peak. 
Fold in the egg whites gently, using cut and fold method. 
Fold egg and cream mixture to the chocolate till thoroughly mixed.
Do not overmix as that will make the mousse flat.
Pour in the prepared mould and freeze for about 4 hours.
De-mould and spray velvet chocolate spray on top to give a coarse and velvety texture.
Garnish with choice of garnish, like mint and gold leaves (optional).