Cream the butter with confectioner’s sugar, salt, vanilla sugar, and lemon zest.
Mix in the eggs and egg yolk little by little.
Mix hazelnuts, cake crumbs, and flour, and mix into the eggs and butter.
Flavor with rum, clove powder, and cinnamon.
Place a 12x18in (30x45 cm) baking frame on a baking sheet or use a deep cake pan.
Pour in about ⅔ of the batter.
Lay down a layer of wafers and brush marmalade on it.
Fill a piping bag fitted with a star-shaped nozzle with the rest of the Linzer batter and pipe a lattice on top.
Sprinkle with almond slices and bake for about an hour.
Let cool and serve.
Notes / Tips / Wine Advice:
Linzer torte can of course be prepared using the same recipe.
For a really successful Linzer dough...
...here are a few old housewives’ tips:
• Don’t use butter that is cold, but also not room temperature. It is best to take the butter out of the refrigerator about half an hour before using it.
• Mix together the ingredients quickly and evenly, so that the dough stays together properly and does not become crumbly.
• If the dough becomes too crumbly, a few drops of milk will help to make it smooth again.
• Kneading the dough will warm it up, so set it in a cool place so that it becomes firm again.
• Poke holes gently with a fork before baking. The dough will rise better in the oven.
• Make sure that the heat in the oven is not over 320 °F (160 °C).