Put flour, butter, icing sugar, and egg into a mixing machine and mix it into a firm dough. Alternatively, you can mix the dough with the dough hooks of an electric mixer. 

Take the dough out of the bowl and gather it on the countertop. Do not knead it, just gather it until it is cohesive. 

Refrigerate the dough for 45 minutes.

 

Roll out the dough to about 1 cm thickness on a lightly floured countertop.

Cut out round cakes - use a glass or a cutter - and place them on parchment paper.  

Bake the cakes for about 10 minutes at 175 degrees Celsius (347 degrees Fahrenheit) with fan.

Remove the cakes from the oven and let them cool on a wire rack. 

Spread raspberry jam on one half of the cooled cakes and place the other half on top. Press the cakes together gently.

Decorate the cakes with thick, white icing and preferably sprinkle with colored sprinkles or freeze-dried raspberries.