Beat the eggs, salt, vanilla sugar and sugar with the whisk of the hand mixer until thick and creamy. Alternately stir in 200 g flour and milk. Leave to swell for about 15 minutes. Mix 50 g flour and baking powder, stir into the dough.
Grease the recesses of a Poffertjes pan with oil. Heat the pan. Fill 1 teaspoon of dough into each of the depressions. Bake at low to medium heat on both sides until golden brown. Remove. Bake more poffertjes in the same way from the remaining dough. Dust with icing sugar and serve with melted butter.