400g High-quality butter, very soft but not melted
200g Granulated sugar
300g Rice flour
120g Tapioca starch
120g Potato starch
60g Rice starch
3g Fine salt
1g Xanthan gum

Cut the butter into cubes and leave it at room temperature until very soft, but NOT MELTED.

Sift the starches, flours, salt, and xanthan gum.
Briefly work the butter with the sugar until incorporated, but do not cream or melt it.

Add the dry ingredients and briefly work the mixture with your hands until smooth, firm, and homogeneous, of course without lumps.

Spread the dough in a non-stick baking tray or one lined with parchment paper, and use your hands to flatten the surface until smooth and compact.
Score the classic “fingers” and prick them with a fork.

Bake immediately as directed.

Remove from the oven, let cool slightly, and retrace the cuts made earlier to properly separate the cookies.

Allow to cool completely, divide, and store in an airtight container for up to 4-5 days.
Don’t worry, they’ll be gone by the evening.

Prosto Biscuits (known locally as biscotìn de Prost in the Chiavennasco dialect) are traditional biscuits from Prosto, a hamlet of the municipality of Piuro in Val Bregaglia.
The recipe dates back more than a century, when these biscuits were prepared at home for festive occasions, especially for the Feast of the Assumption on August 15. At that time, the biscuits were baked in the village’s only oven, Il Mulino, owned by the Del Curto family, located next to the local church.
The biscuits are made with simple ingredients - flour, sugar, and above all a generous amount of butter - and can easily be prepared at home. Although they originate specifically from Prosto, they are considered a characteristic sweet of the entire Valchiavenna area and are traditionally served at the end of meals in the region’s typical crotti.
They have been officially recognized as a Traditional Agri-food Product of Lombardy.
[Source: Wikipedia]

Prosto Biscuits from Valchiavenna win you over at the very first bite thanks to their generous amounts of butter, sugar, and flour, which give them a rich flavor and an irresistibly crumbly texture. In this gluten-free version, they are shaped like classic Scottish Shortbread, closely resembling them in both structure and character.

The original Prosto Biscuit recipe is carefully preserved by the historic “Del Curto” bakery in Prosto, which still produces them today and distributes them in their distinctive colorful paper packaging. If you have the chance and do not have gluten restrictions, a visit to the Prosto bakery is highly recommended to enjoy these buttery, traditional, and truly unique biscuits.

If you prefer a more golden biscuit, once they have cooled, place them well spaced on a baking tray and return them to the oven at 160C For 10/12Minutes.

This recipe can serve as a starting point for even more indulgent variations. The dough can be customized and flavored with vanilla, citrus zest, honey, cocoa, and more, to create tempting and irresistible versions.

Xanthan gum can be omitted - it helps keep the dough compact but is not essential.

Respect times and temperatures to obtain biscuits that are crumbly, fragrant, and perfectly colored.