We need a baking tray the size of a sheet. We lined it with baking paper.
First top: Beat the egg whites hard with a pinch of salt and sugar. Beat until the sugar crystals are gone and it's hard. Add flour and ground walnuts, and mix with a spoon by turning from bottom to top. Pour the composition into the baking tray and level. Put the tray in the preheated oven at 180 degrees and let it bake (about 15 minutes) or until browned.
Beat the egg whites with a pinch of salt and sugar until you get a hard foam. Add coconut flakes and flour and mix from bottom to top. In the prepared tray (of the same size as the first one, or the one in which I baked the first top but cooled) we pour the composition, level it and put it in the oven until it browns.
Cream : Mix the remaining yolks from the countertops with the sugar and the seeds from the vanilla bean (cut it long and scrape the seeds with a knife). Put the bowl on low heat and mix until it becomes a soft cream, like sour cream. Let it cool.
We mix the soft butter until it foams. With a spoon, take the egg cream and add it over the butter, mixing lightly with the spoon or with the mixer on low speed.
Now that we have everything ready we can assemble the cake
Divide the cream into 3 equal parts. Place the first wafer sheet (preferably in a tray or on a plate), put some cream and level. Place the first top, and put another part of cream on top. Level, place the second worktop and the last part of the cream. Place the wafer sheet on top and let it cool with something heavy on top so that the top sheet does not bend and the cream cream sticks to the sheets (I used a wooden bottom)