Step 1: 1. Mix the milk, sugar, gelatin and cornflour. Keep stirring till it boils. Add chocolate and stir till the chocolate melts completely. Once the chocolate has melted completely, let it cool.
Step 3: 2. Once the mixture has cooled, add whipped cream and vanilla essence to it. Give this mixture a good stirring/whip to ensure that everything is properly mixed and to get a good thickness to your mixture.
Step 5: 3. Mix the biscuit powder and butter properly. Place it in the container you wish to serve your mousse in and press gently, so as to cover the base. Repeat it till you have covered all your containers.
Step 7: 4. Then, add the chocolate mixture on it. Cover this with a thin layer of your chocolate ganache and place it in your refrigerator for 2-3 hours to set. Your chocolate mousse is ready.