Spettekaka
88 g (3.1 oz) egg yolks
28 g (0.99 oz) egg whites
260 g (9.17 oz) icing sugar
24 g (0.85 oz) potato starch

Royal icing
120 g (4.23 oz) icing sugar
60 g (2.12 oz) caster sugar
30 g (1.06 oz) egg white
5 g (0.18 oz) freeze dried strawberries

Instructions

Spettekaka
Preheat the oven to 100° C (212 degrees Fahrenheit).
Prepare a baking tray with baking paper.
Whip the icing sugar, egg yolks and egg whites until white and fluffy.
Fold in the potato starch.
Transfer the batter to a piping bag with a very small round tip.
Pipe 15 squares with a sparse zig-zag pattern inside.
Bake the first layer for 10 minutes.
Pipe another sparse layer of the batter on top of the first layer. Bake for 10 minutes.
Continue adding layers and baking them until the batter is used up.
Keep the cake pieces in the oven until they are completely dry, approximately 15 minutes.

Royal icing
Mix some icing sugar and freeze dried strawberries in a food processor or blender until the
strawberries are completely powderized.
Prepare a boiling pot of water with a heat proof bowl on top to make a water bath. Put the egg white and caster sugar in the bowl. Stir constantly until the mixture reaches 72° C (161.6 degrees Fahrenheit). Take the bowl off the heat and continue to whisk until the mixture is cool.
Add some of the pink icing sugar. Whisk by hand while adding more icing sugar in small batches and whisking a minute inbetween each batch. Continue until the icing is thick enough to hold stiff peaks, but still soft enough to flow though a piping bag.
Put the icing in a piping bag with a very small tip, approximately 2 mm.

Assembly
Stack all the layers with a small amount of royal icing in between each layer to act as a glue.
Pipe the royal icing on top and on the sides of the cake.
Drizzle some pearl sugar on the serving plate.