1. Place the icing sugar in a bowl, add most of the egg white and mix to form a runny paste.
2. Knead the almond paste to soften and flatten into a thick disc shape. Add the icing sugar paste little by little and knead into the marzipan. Keep adding until you have a soft paste. Shape into a ball then roll into a cylinder shape.
3. Wrap in cling film and place in the fridge for at least four hours.
4. Line 2 large baking trays with parchment paper and heat your oven to 190°C.
5. Take the dough cut into 4. Roll each piece into a long rope approximately 2cm thick.
6. Place the chopped pistachios in a large baking tray and gently roll the marzipan ropes in the pistachios to coat. Gently tap the front of the rope with the heal of your hands to make the ropes a triangle shape. Run a pallet knife under to loosen. Repeat with the remaining dough.
7. Begin to cut the dough into strips ready to make the rings. The smallest ring with be made from a strip measuring 8cm the next 10cm and continue in 2cm increments until you have 13 strips. The largest will be 32cm long.
8. Fold the strips into a round and push the edges together to seal.
9. Make sure the curved surface is on the outside of the ring. The smaller rings are the hardest to make, take your time to shape them. Place the rings on the prepared trays.
10. Place a piece of parchment on top of each tray of rings. Take an empty tray and sit it on top of the parchment and press gently to flatten the top of each ring. Remove the tray and parchment and bake the rings for 10-12 minutes.
11. Once the rings have cooled begin to build the tower. Have your serving plate to hand. Take the largest ring and dip the base in the melted chocolate, place into the centre of the plate. Repeat with the remaining rings until your tower is complete.
12. Dust with icing sugar before serving.