For the dough, stir the butter, sugar, lemon zest and vanilla sugar until frothy. Gradually add the eggs and stir in. Finally, stir in the nuts, flour, baking powder and rum.
Spread the dough on a baking tray lined with baking paper, cover with the pitted and halved apricots. Bake at 170 ° C for about 45 minutes. Sprinkle with powdered sugar.