I always use this recipe, it hasn't failed yet.
# Add one medium sized egg white to 250g sifted icing sugar and a drop of vanilla essence, mix to a dough.
# Divide into 8 portions and roll into a ball.
# Cook on grease proof paper, 2 at a time for 1 minute and 20 sec on full power - WATCHING CONSTANTLY, because when it 'happens', it happens quickly. You'll see what I mean lol.
.. and I haven't been, or planned to be in Germany for the last 29 years or so, you must've got me mixed up with someone else. :-)