For the base gently melt the butter, add the crushed digestives and mix well. Press firmly into the base of the tin and leave to chill until firm
For the filling put the gelatine into cold water to soften, then dissolve it into 50ml of water over a very gentle heat. set aside to cool
In a large bowl beat the mascarpone, soft cheese and icing sugar together until smooth. be careful not to overmix.
Stir through the gelatine mixture, nuts and nougat pieces and vanilla just until combined. Spoon half the mixture into the tin to make a smooth top. Repeat with the remaining mixture and return to the fridge to set for at least 4hrs or overnight