Essi buranelli (not a cure for cholesterolemia)

I eventually managed to find THE original recipe for essi buranelli, the delicious pastry biscuits from Burano, from Sara, from Burano (of course), who makes superb ones... as they're so yellow, I imagined there were many eggs, but I didn't think that many! The sugar quantity is sky-rocketing as well, but I wanted to try them the way I was told, and they're actually delicious. I want to try again though by reducing the amount of sugar, to see if the result is at least similar. Besides, it's understandable that traditional pastry from older times are so rich, seeing that you ate them a few times in a year. So, my advice is: prepare them in the old fashion way for special occasions, and go for a lighter version if you think to eat them often.

1 kg wheat flour
300g butter
12 egg yolks + 1 egg white
600g sugar
1 tbsp rhum
vanilla flavour

Cut the butter into pieces and let it soften at room temperature. Beat the egg yolks with sugar, rhum and vanilla, keep the egg white aside (you will need it to soften the dough should it be too hard). Start pouring the flour little by little; when you have put it all, start with the butter, working the dough by hand until you get a ball. Pre-heat the oven at 200°C. Form the S by hand by making a cylindre first, about 10cm long and 3cm large -important Sara's tip: never press to hard the dough- and then giving it the S shape. Bake for 10-12 minutes, they have to get golden but not too dark, otherwise they'll get too hard. Now try them and let me know!