Stuffed Kulich

Warm the milk to 105°F (40°C), add the yeast, a bit of sugar, and flour, mix well, cover with plastic wrap, and let rise in a warm spot for 15 minutes until bubbly.

Whisk the eggs with the sugar until fluffy, then fold in the softened butter and combine.

Stir in the sponge starter gently, then add the sifted flour and knead into a smooth dough for 10-15 minutes.

Plump the raisins in boiling water for 5 minutes, then pat them dry with paper towels.

Fold the raisins and orange zest into the dough, cover, and let proof in a warm place for 1.5 hours.

Divide the dough into baking molds, filling them one-third full, and let rise for another hour.

Bake in a preheated oven at 350°F (180°C) until golden brown, about 25-30 minutes, testing for doneness with a skewer.

Frost the cooled kuliches with icing.