How to make
Beat the egg whites along with the sugar, salt and vanilla sugar. The mixture should be bubbly, not smooth.
Pour the melted lard and condensed milk and beat again briefly, until a homogenous mixture is obtained.
Add the starch with the baking powder in parts and when the mixture becomes thick, knead the cookie dough by hand. If it seems too thin, add more starch.
Tear off balls of about 0.7 oz (20 g) each and arrange them spaced apart in a tray lined with baking paper or a greased one. The dose is for two of the standard trays, that are in every oven. My advice is to form all the balls at once, rather than waiting for one tray to bake and then making the balls for the second. This is done, because the dough will dry out on the surface and become crumbly and harder to shape.
Put them in an oven heated to 320°F (160°C) for 10-15 minutes. Do not wait for the cookies to turn aquire a golden color, since they should remain white with a barely noticeable delicate golden color.
Store these delicate snow white cookies in a tightly sealed container for up to a week.
Enjoy!