For the filled nut buns, beat egg whites, sugar, lemon zest and juice for at least 5 minutes until stiff, mix nuts and flour and fold in carefully.
Pour the mixture into a piping bag and pipe small nuts onto a baking tray lined with baking paper and bake at 180 °C for about 10 minutes.
Cream the butter with the sugar, stir in the melted chocolate and rum flavoring and pipe small dots onto the nut gnocchi using a piping bag.
Chill, heat the chocolate glaze, coat the nuts with it and let them dry on baking paper.