Beat butter with sugar in a bowl until they turn white. Also beat the egg yolks and add them to the mixture. Heat the milk and add ammonia. Stir until it swells up.
Pour the milk into the yolk-sugar mixture and stir. Then beat the egg whites until they turn to meringue and also add them in the mixture, together with the vanillas.
Add flour little by little until the dough thickens, but doesn't become too tight. Form the buns in a shape of your liking. Place the buns in a pan paved with parchment paper and spread them with a little beaten egg. Bake in a preheated oven at 180 degrees for about 25' minutes.