Place the loaf tin onto a piece of baking paper and draw around the base of the tin 3 times to create 3 templates. Carefully cut out with some scissors.
Pour chocolate onto each template and smooth it over until the baking paper is covered. Transfer to a clean baking tray to remove the excess chocolate from around the edge and place in the freezer until set.
In a bowl beat together the egg whites and icing sugar until smooth and glossy. Beat until the mixture holds its shape for a few seconds when using a beater to draw a figure of 8 with some of the mixture.
In a separate bowl beat the cream until soft peaks form before folding in the egg and sugar mixture. Add ⅓ of the mixture to a piping bag fitted with a petal tip. Keep this in the fridge until needed.
In a separate bowl beat the banana with some double cream until smooth. Fold into the remaining cream mixture. For ease, I add this to a piping bag, no tip needed, just cut the end off.
To assemble, line the loaf tin with baking paper before placing in the first layer of chocolate, (don’t forget to remove the baking paper template from the back first).
Pipe banana ice cream over the chocolate and smooth over with the back of a spoon. Lay the 2nd chocolate template on top and garnish with caramel sauce, fudge pieces and crushed digestive biscuits. Repeat until you are at the top of the tin, I always prefer to finish with ice cream. Place in the freezer until set.
Once completely set, remove from the tin and place onto a serving plate. Decorate the outside of the Viennetta with the first piping bag filled with ice cream. Using a petal tip wiggle the piping bag up and down while moving along the bottom of the Viennetta and repeat on the top. Drizzle with more caramel sauce, fudge piece and digestive crumbs. Enjoy :D