Quick Bread Version
Lightly grease a 9×5 loaf pan with butter or line with parchment paper, and set aside.
Preheat your oven to 350°F (175°C).
In a small bowl combine the cinnamon swirl ingredients of cinnamon and sugar, and set aside.
In a large bowl, whisk together the flour, baking powder, baking soda, and salt.
In another bowl, combine the cup of sourdough starter, sugar, butter or oil, eggs, milk, and vanilla. Mix until well combined.
Add the wet ingredients to the dry ingredients and stir until just combined. Do not overmix.
Mix in the raisins.
Pour half of the batter into the prepared loaf pan. Sprinkle half of the cinnamon swirl mixture evenly over the batter. Pour the remaining batter on top, and then sprinkle the remaining cinnamon swirl mixture over the top layer of batter.
Use a knife or skewer to gently swirl the cinnamon mixture through the batter in the pan, creating a marbled effect.
Pour the batter into a prepared loaf pan.
Bake in the preheated oven for about 55-65 minutes, or until a toothpick inserted into the center of the bread and comes out clean. If the top starts to brown too quickly, you can cover it loosely with aluminum foil.
Let the sweet bread cool in the pan for about 10 minutes, then transfer it to a wire rack to cool completely.
Slice and enjoy your homemade bread!
Long Fermented Version
Begin the batter 16-18 hours before you plan to bake the cinnamon raisin quick bread. This allows the sourdough starter to ferment the flour, enhancing its digestibility and nutrient availability.
In a large bowl, whisk together the flour, baking powder, baking soda, and salt.
In another bowl, combine the cup of sourdough starter, sugar, butter or oil, eggs, milk, and vanilla. Mix until well combined.
Add the wet ingredients to the dry ingredients and stir until just combined. Do not overmix.
Mix in the raisins.
Cover the mixture with a damp kitchen towel or plastic wrap.
For best results, allow for a 4-6 hour rise time.
Place dough into the fridge for the second rise and let it continue fermenting overnight for an additional 12 hours.
The Next Day
The next morning, after the final rise, preheat your oven to 350°F (175°C).
In a small bowl combine the cinnamon swirl ingredients of cinnamon and sugar, and set aside.
With a Danish dough whisk or a wooden spoon, give the cinnamon sourdough dough a few good stirs.
Pour half of the batter into the prepared loaf pan. Sprinkle half of the cinnamon swirl mixture evenly over the batter. Pour the remaining batter on top, and then sprinkle the remaining cinnamon swirl mixture over the top layer of batter.
Use a knife or skewer to gently swirl the cinnamon mixture through the batter in the pan, creating a marbled effect.
Bake for 55-65 minutes. Stick a long toothpick in the center and when it comes out clean it is ready.
Let the sweet bread cool in the pan for about 10 minutes, then transfer it to a wire rack to cool completely.
Slice and enjoy your homemade loaf of bread!