Whisk together the eggs, a pinch of salt, and sugar until the sugar dissolves. Add the butter and honey, whisk again thoroughly, and place the mixture over a double boiler. Stir occasionally for 15 minutes. The mixture should be heated until it’s almost boiling but must not boil.
Remove from the double boiler and add the baking soda. Stir well; at this point, the baking soda will react with the honey.
After a few minutes, add the sifted flour. Incorporate as much as you can using a hand whisk or silicone spatula, then transfer the dough to a floured surface and knead it into a soft dough.
The dough may initially be sticky, but after chilling in the fridge, it will thicken and no longer stick to your hands. It’s best to start with 600 g of flour and add extra while rolling if needed.
Divide the dough into 10 portions, place them on a floured plate, cover with plastic wrap, and refrigerate for 1 hour.
Roll each portion into a 2-3 mm thick circle, and cut out 30 cm diameter rounds. Save the leftover dough for the crumbled topping. (Tip: Roll the dough directly on the parchment paper you’ll bake it on, as it makes transferring easier after baking.)
Pierce the dough rounds thoroughly with a fork, place them in a preheated oven at 170°C, and bake for 5 minutes.
Remove the baked layers from the parchment paper while still warm. Repeat with the remaining dough portions.
With the leftover scraps, roll and bake an 11th layer, which will later be crumbled and used as a topping for the cake.
