The yeast is dissolved in 1 cup of lukewarm milk with a bit of sugar and 1 tablespoon of flour. Once activated, add the sifted flour with the remaining sugar, milk, pinch of salt, eggs, lemon zest and add a bit of butter and knead a smooth and elastic dough.
Allow to rise in a warm place until doubled in volume. Mix again and divide it into 3 balls that are rolled out into sheets of 0.5″ (1 cm) thick, smeared with jam and sprinkled with walnuts. Roll them up.
Put them into greased form and allow to rise again. Then coat them with a beaten egg yolk and sprinkle with plenty of sugar. Bake until ready in a moderately heated oven.