For the apricot dumplings with butter-cinnamon crumbs, mix all ingredients, except apricots and sugar cubes, into a smooth curd dough. Chill dough for about 30 minutes.
Cut apricots in half, remove seeds and place 1 sugar cube in each apricot. With floured hands, wrap dough around fruit. Form dumplings and cook in simmering water for 10-15 minutes.
For the butter-cinnamon crumbs, heat the butter, sprinkle in the crumbs and cinnamon, and toast until lightly browned. Arrange the apricot dumplings with butter-cinnamon crumbs and serve.