Thaw the pitted cherries, add the sugar, and let sit for an hour so they release their juice.

Mix the melted, cooled butter with the sour cream, baking powder and vanilla sugar. Fold in the sifted flour in two additions, knead a non-sticky dough, shape into a ball, and chill for 1 hour.

Divide the dough into 15 portions. Roll each into a thin rectangle 22-25 cm long and no wider than 6 cm.

Spread the cherries along the strip, pinch the edges together well, going over the seam a couple of times, flip seam-side down, and place on a parchment-lined tray. Prick each log lengthwise with a skewer.

Bake for 15-20 minutes at 180°C until golden, and let cool.

For the frosting, strain the sour cream through cheesecloth or a sieve, add the powdered sugar, and beat well with a mixer.

Assemble the hut: arrange 5 logs, drizzle with cherry juice and spread with frosting, then 4, 3, 2 and 1 log, soaking and frosting each layer.

Coat the hut with the remaining frosting on top, sprinkle with chopped walnuts if you like, and chill for at least overnight.