Beat the softened butter with the sugar and salt, until light and fluffy.
Stir in the eggs one by one.
Mix, flour, nuts, baking powder, cinnamon and clove powder, and fold into the mixture. Now the batter is ready.
Spread about ⅔ of the batter on a baking tray with baking paper.
Mix the jam well, and spread on top of the batter.
Fill the remaining batter into a piping bag and pipe a border around the jam.
First pipe diagonally, lengthwise stripes.
Then pipe the stripes in the other direction to form a grid. Do not pipe the stripes too close.
Bake in preheated oven at 180° C for about 40 minutes.