Povitica (Walnut Cinnamon Swirl Bread)

For the dough:
Combine yeast, 1 tablespoon sugar, and half of the warm milk in a bowl and let sit until foamy (about 10 minutes). Once foamy, mix in remaining sugar and milk, salt, butter, and egg.

While stirring, slowly mix in flour until dough is formed. Cover with plastic wrap and set in a warm place until the dough has doubled in size, about 1 hour.

For the filing:
In a food processor, purée walnuts, sugar, butter, milk, and cinnamon into a smooth paste. Beat egg whites until frothy and slowly mix in walnut paste.

Use butter to grease a 9 x 5 x 2 3/4 inch loaf pan.

On a lightly floured surface, roll out dough into a 12 x 5 inch long oval about 1/9 inch thick. Evenly spread walnut mixture onto the dough with a spoon.

Starting on one end, tightly roll the dough into a loaf and transfer to pan. Set in a warm place for about 1 hour until doubled in size.

Heat oven to 350°F. Bake until a knife inserted in middle comes out clean, about 1 hour. Let cool and enjoy!