Mix the butter and sugar together. Stir in eggs. Knead in the flour mixed with baking powder. Chill the dough for 30 minutes. Roll out on a well-floured work surface and cut out molds. There must be the same number of motifs.
Use a thimble to cut a hole out of half of the biscuits, as the biscuits will be filled with jam. Place on a baking tray lined with baking paper.
Bake at 200 ° C top and bottom heat or 180 ° C hot air for about 10 minutes. The cookies must still be light.
After cooling down to half without a hole, spread a sour jam (e.g. currant) and put the other half with the hole on top. Finally dust with powdered sugar.
The cookies save themselves well in a tin or Tupperware and taste particularly good if they have been steeped for a few days.