First, preheat the oven to 170 °C. Butter a baking tray and sprinkle with flour. Cream butter, powdered sugar, salt, cinnamon, clove powder, vanilla sugar and grated lemon zest. Slowly beat in eggs and yolks. Fold in flour, nuts and baking powder.
Spread 3/4 of the mixture on the baking sheet, cover with wafers and spread with jam. Mix the rest of the mixture with the 2 tablespoons of flour and pipe a lattice onto the cake using a piping bag.
Sprinkle the flaked almonds on top and bake for about 35 minutes.
Remove the Linzer cake with spelt flour and let cool covered.