For the Dough
- 3 1/ 4 cups all-purpose flour
- 1 cup mature sourdough starter
- 3/ 4 cup milk
- 1/ 4 cup plus 1 1/2 teaspoons granulated sugar
- 1 large egg
- 1 1/ 2 teaspoons salt
- 1/ 4 cup butter, cubed, at room temperature
For the Filling
- 2/ 3 cup light brown sugar
- 1/ 4 scant cup all-purpose flour
- 1 tablespoon butter, melted
- 1 tablespoon ground cinnamon
- 1 teaspoon ground cardamom
- 1/ 8 teaspoon salt
- 1 orange, zested
To make the dough: combine the flour, starter, milk, sugar and egg in the bowl of a stand mixer fitted with the dough hook. Mix on low until the dough comes together and there are no dry bits left, about 3-4 minutes. Set aside to rest for 30 minutes.
Add salt to the dough and mix on low for 1 minute. Increase the speed and mix until the dough becomes elastic and stronger, 4-5 minutes. Reduce speed to low and add the softened butter, one cube at a time, until each is incorporated. This may take 4-5 minutes.
Once the dough begins to ball up around the dough hook, transfer to a covered container to ferment. Keep at a warm room temperature (about 76ºF) for 4 hours. Fold it in the container about once an hour.
Refrigerate the dough for 1 hour up to overnight.
To make the filling: mix all ingredients together in a bowl until well combined.
To assemble: Lightly grease a 9 x 5-inch loaf pan with butter. Set aside. Once chilled, turn the dough out onto a floured surface and roll into a 15 x 20-inch rectangle with short sides on the left and right. The dough will still be a bit thick.
Spread the filling evenly over the dough. Roll the dough tightly, starting with one of the short sides. Cut the cylinder lengthwise in half with a sharp knife.
Place one strip over the other in the middle to form an X, the cut sides facing up. Continue to twist the halves around each other from the middle to the top, then from the middle to the bottom. Transfer the twisted dough into the prepared loaf pan. Cover loosely in a plastic bag and let rise for about 2 hours, until puffed above the edge of the pan.
Preheat the oven to 400ºF. Once risen, bake for 35-50 minutes, or until internal temperature reads 190ºF. Let cool in the pan for 5 minutes, then remove from pan and finish cooling on a wire rack.