Double Chocolate Mousse Cake

Instructions

For the Crust:

1. Crush the sandwich cookies into fine crumbs. You can use a food processor or put the cookies in a resealable plastic bag and crush them with a rolling pin until fine crumbs form. 
2. Add the melted butter and stir until well combined. 
3. Grease a 7in (18cm) removable bottom round pan with vegetable oil or cooking spray. 
4. Press the crumbs into the bottom and 1-inch (2,5cm) up the sides of the pan.
5. Refrigerate while preparing the ganache. 

For the Semi-Sweet Chocolate Ganache:

1. Combine the semi-sweet chocolate and heavy cream in a medium bowl. Microwave in 30-second intervals, stirring after each interval until smooth. 
2. Add the butter and stir until well combined. The heat of the chocolate will melt the butter. 
3. Pour the ganache into the cookie crust and smooth the top. 
4. Refrigerate for about 30 minutes until it starts to firm up. 

For the Milk Chocolate Mousse:

1. Combine the milk chocolate and heavy cream in a medium bowl. Microwave in 30-second intervals, stirring after each interval until smooth. Let it cool at room temperature for a few minutes until slightly warm. 
2. Pour the water into a small bowl. Sprinkle powdered gelatin on top and stir until well combined. Let the mixture stand at room temperature for about 5 minutes to bloom. The gelatin will absorb the water. 
3. Microwave for about 10 seconds and stir. Don’t overheat the mixture or the gelatin will lose its setting powder. 
4. Pour the melted gelatin over the chocolate mixture and stir until well combined. Let it cool completely at room temperature.
5. Beat the cold heavy cream until stiff peaks form. Using a wire whisk, gently mix the whipped cream into the chocolate mixture in three additions. 
6. Pour the mousse over the semi-sweet ganache layer and smooth the top.
7. Refrigerate for at least 4 hours or overnight until firm. 
8. Unmold the dessert, sift cocoa powder on top and decorate with chocolate shavings.