Cover the base and sides of an 18 x 28cm slice tin with a sheet of baking paper. It's important to make sure you leave paper hanging over the sides.
Melt the white chocolate in the microwave - cooking for 30 second spurts and once melted set aside to cool slightly.
Add the gelatine to a cup of boiling water and stir to combine.
Crush chocolate ripple biscuits in either a food processor, or using a rolling pin until they resemble fine crumbs. Add the melted butter and stir to combine. Press the crumbs in the base of the slice tin and place in the freezer to chill for 30 minutes.
While the base is chilling, combine the cream cheese, sugar. peppermint essence and food colouring using an electric mixer until smooth. Add the cream and mix to combine.
Stir through the gelatine mixture and white chocolate.
Spoon the mixture over the chilled base and decorate with the Aero Balls and refrigerate for 6 hours or until the slice has set.