Beat the butter, yolks and powdered sugar until creamy. The curd must be really firmly expressed and already have crumbly consistency.
Mix cornstarch with rum and add to the creamed mixture with lemon zest, flour, vanilla and curd and knead well.
Surround each apricot with a little dough and roll into a ball. Steep in lightly sweetened boiling water for 10 minutes.
Fry breadcrumbs and powdered sugar in a frying pan until the crumbs take color.
Arrange the dumplings and serve sprinkled with the breadcrumbs.