BBC Food has a simple and easy-to-follow recipe for povitica filled with walnuts and cocoa powder. The recipe takes up to four hours to prepare and cook.
To make BBC Food's recipe, add 300 grams flour and 40 grams sugar to a mixer. Add 7 grams salt and 10 grams yeast. Add 30 grams melted butter, 1 egg, 1/2 split vanilla pod with seeds removed and 150 milliliters milk. Mix on low, and then medium until the dough is smooth.
Transfer the dough to a greased bowl, and cover. Let rise for one hour. In a saucepan, heat 60 grams butter and 4 tablespoons milk. In a food processor, add 280 grams walnut pieces, 1/2 split vanilla pod with seeds removed, 100 grams sugar and 2 tablespoons cocoa powder. Add 1 egg yolk and butter mixture.
Place a sheet on a hard surface, and dust with flour. Roll the dough into a 20 by 12-inch rectangle, and brush with 15 grams butter. Stretch the dough to a 40 by 24-inch rectangle, and top with filling. Roll the dough into a log, and lay in a greased tin to form a U shape. Form a second U shape on top. Let rise covered for one hour, and preheat the oven to 350 degrees F. Brush with egg white, and bake for 15 minutes. Reduce the heat to 300 degrees F, and bake for another 45 minutes. Combine 100 grams icing sugar with cold water, and drizzle over the povitica.