Preheat your oven to 410F(210C). In the stand mixer, place the egg whites, icing sugar and vanilla extract then start mixing it on low to medium speed until throughly combined. The dough must be firm but not dry and feel just a little sticky but not sticky enough that it sticks onto your fingers. Shape the dough into a ball. Cover it with plastic wrap and place it in the refrigerator overnight.
Grease the ring moulds with some melted butter and sprinkle some flour on them. The moulds should only be covered with a thin layer of flour. You can use a meat grinder or roll the dough into rolls the width of your finger and sit them in the mould.
Roll the dough and combine the ends of the dough together to make the rings. Repeat with the remaining pieces of dough until you have 6 moulds each containing 3 circles of dough. While you are doing that, keep the dough covered with kitchen towel so that it does not dry out. Put the moulds on a baking tray and bake it in the oven for 10-12 minutes until golden brown. Remove it from the oven and leave it to cool on the moulds until they get hard. Then transfer to a wire rack to cool completely.
For the icing, mix egg whites and icing sugar until it has a smooth consistency. Once the rings have cooled, organize the Kransekake by ring sizes to build the tower and pipe the icing onto the rings into thin, zig-zag like patterns. Repeat with the remaining rings until your tower is complete. Enjoy!
Note: Kransekake can be stored frozen for a up to a month.
