Sweet Cinnamon Raisin Sourdough Swirls

1. In a large bowl, combine the all-purpose flour, whole wheat flour, sugar, salt, and cinnamon. 2. Add the sourdough starter and warm water to the dry ingredients and mix until a sticky dough forms. 3. Knead the dough on a floured surface for about 8-10 minutes until smooth and elastic. 4. Transfer the dough to a lightly greased bowl, cover with a damp cloth, and let it rise in a warm place for 4-6 hours or until doubled in size. 5. Once the dough has risen, punch it down and roll it out on a floured surface into a rectangle (about 16x12 inches). 6. Spread the softened butter evenly over the dough, then sprinkle the brown sugar and raisins on top. 7. Starting from the long side, carefully roll the dough into a tight log. Pinch the ends to seal the seam. 8. Cut the log into 12 equal slices and place them in a greased baking dish or on a parchment-lined baking sheet, cut side up. 9. Cover the rolls with a kitchen towel and let them rise for another 1-2 hours until puffy. 10. Preheat the oven to 350°F (175°C). 11. Whisk the egg and brush it over the top of the rolls for a shiny finish. 12. Bake in the preheated oven for 25-30 minutes or until the rolls are golden brown. 13. Let the rolls cool slightly before serving.