Knead on a lightly floured board very briefly and pat into a disc. Place dough in a ziplock plastic bag and let rise until double, about 45 minutes. Divide dough in half. Spread one cup of filling on each section. Roll up in jellyroll fashion and place, seam side down, on baking sheet.
Press roll down slightly.
Brush each roll with beaten egg yolk and make several diagonal slashes on top. Cover with a damp tea towel and let rise - about 40 minutes. Cool well before cutting into serving pieces. Cover very well with plastic wrap to store. Pastry comes out of the oven slightly puffy.