Toss biscuit crumbs and butter together in a bowl. Press mixture into the bottom of a 24cm spring form pan.
Melt the chocolate in a bowl over hot water, add the NESCAFÉ instant coffee, stir until well combined and remove from heat.
Stir in the egg yolks and the vanilla powder into the chocolate mixture. Mix well.
Add NESTLÉ® Cream and stir gently until well blended.
Whisk the egg whites until soft peak form. Add the caster sugar then fold into the chocolate mixture.
Turn the chocolate mixture into the spring form, cover with aluminum foil and freeze for 12 hours.
To serve, turn the mousse out onto a serving plate and remove paper.
