Mix flour, sugar, ginger, cinnamon, baking powder and salt. Heat the butter and syrup until the butter has melted. Pour into the flour mixture while stirring constantly and work into a smooth dough. Stir in the eggs one by one. Spread the dough on a greased baking tray (32 x 39 cm).
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 30 minutes. Leave to cool at lukewarm temperature. Warm up the jelly, stir until smooth and spread on top. Cut into rhombs (6 x 8 cm) and decorate with candied ginger if desired
Waiting time approx. 30 minutes