Add the spruce tips, the honey and the water and let it soak overnight. Sieve the syrup before use.

Preheat the oven to 160°C/320F.

Place in a blender the sugar and the mint leaves and blend until the sugar will turn green.

Add a small pinch of salt to the eggs and beat them for at least 10 minutes, adding little by little the mint sugar.

Add to the mixture the sieved flour and potato starch and carefully mix the batter with a spatula (do not overmix!).

Place baking paper and grease the borders of two 4.5 inch (11,5 cm) springform pans and divide the batter into the two pans.

Bake both cakes at the same time (they are so small that they fit together!) for 25 minutes. Check if the cakes are cooked by inserting a toothpick into the cake: if it will come out clean, the cake is cooked.*

In a bowl, whip the cream cheese, the powdered sugar, the heavy cream and the lemon zest until the frosting will be homogeneous and firm.

Once the cakes are cooled, remove them from the springform pans, even them out with a knife and cut them into two lengthwise, so as to have four layers.

Place the first layer on a plate or cake stand, moisten it with the spruce tip syrup and spread a thin layer of frosting, levelling it out.

Repeat the procedure for all the layers and cover the cake top and sides with a very thin layer of frosting. Place the cake and remaining frosting in the refrigerator for at least half an hour to let them harden and stabilize and frost the cake a second time with a thicker layer of frosting.