I bake these star-shaped soft biscuits every year in the build up to Christmas and the kids love sandwiching them together with jam. You could also cut out Christmas tree shapes, if you prefer.
Combine flour, butter, sugar, egg, baking powder and vanilla sugar in the bowl of a food processor; process until the mixture comes together to form a dough. Chill the cookie dough in the fridge for 1 hour.
Preheat oven to 180 C / Gas 4. Lightly grease a baking tray.
Roll out the dough to about 1/2cm thick and cut out stars of two different sizes. Place on the baking tray.
Bake in preheated oven for 8 to 12 minutes. Allow to cool slightly and spread the back of the smaller stars with jam. Press onto the larger stars and let cool completely. If you like, dust with icing sugar.