Combine the flours, salt, sugar, the zest of 1 grated lemon and the vanilla seeds, after cutting in with a knife.
Either using a planetary mixer with a paddle attachment or by hand, mix the preciously combined dry ingredients with the egg yolk and the cold butter cut into small pieces until you obtain a roughly blended mixture.
Take a portion of it and press it down onto the bottom of a buttered and floured springform cake tin until you have a very compact base. Create the edges too.
Leave to rest in the fridge for 10 minutes. Meanwhile, clean and dice the apples.
Stir in the Zenzero Fabbri syrup, water and grated lemon zest and caramelise slightly.
Then take the tin out of the fridge and fill it with the sautéed apples. Add the Zenzero Fabbri nuggets cut into slices, leaving a couple aside to use later.
Sprinkle the surface of the cake with the remaining dough “crumbs”. Bake in the oven at 150°C until the crumbs are golden brown.
Leave to cool and garnish with Zenzero Fabbri nuggets, either whole or cut to taste, and a dusting of icing sugar.