Spitzbuben Biscuits

Line a baking tray with baking paper. Cream the butter with the sugar, then add the vanilla sugar, lemon zest and salt. Add the eggs one at a time. Combine the flour with the baking powder and mix in briefly to form a dough. Chill for 30 minutes. Roll out the dough to 5 mm thickness. Cut rings from one half and rounds from the other. Bake at 180 °C for about 8 minutes. Let cool, spread the rounds with jam, dust the rings with icing sugar and place them on top.