1. Blitz cookies until fine, add melted butter and stir to combine.
2. Press into a 20-23cm loose-bottomed cake tin lined with baking paper.
3. Whisk cream, castor sugar and vanilla to medium stiff-peak stage.
4. Divide mixture between two bowls and chill in fridge.
5. Melt dark chocolate in a glass bowl over a pot of boiling water until smooth. (This is the best way to melt chocolate as the heat is more even than in a microwave.) Set aside.
6. Add sponged gelatine to lukewarm coffee.
7. Microwave for 20-30 seconds, or heat in a pot over low heat, just until gelatine melts – don’t let it get too hot.
8. Halve gelatine-coffee mixture.
9. Whisk half the mixture vigorously into melted dark chocolate, then whisk into bowl of chilled cream until smooth.
10. Spoon over cookie base in cake tin and chill for 20 minutes.
11. Repeat process with remaining gelatine, milk chocolate (melted) and chilled cream, spooning mixture on top of semi-set dark chocolate layer.
12. Chill mousse cake for 3-4 hours, or overnight for best result.
13. For ganache, heat cream to hot but not quite boiling.
14. Pour over white chocolate in a bowl and stir until melted.
15. Set aside to cool to room temperature.
16. Pour cooled ganache onto cake, spreading over the entire surface. (Work quickly, as the cold cake can make ganache set quicker.)
17. Chill cake for another 30 minutes.
18. Run a warm cloth around outside of cake tin, then run a hot knife inside around the rim to loosen cake.
19. Remove from tin and slice with a slightly warmed knife (wipe the blade clean between every cut for perfect slices)

Recipe Source: PnP Fresh Living