Lightly grease a 9x5 loaf pan with butter or line it with parchment paper, then set it aside.
Preheat your oven to 350°F (175°C). In a large bowl, whisk together the flour, baking powder, baking soda, salt, and cocoa powder.
In another bowl, mix together the cup of sourdough starter, sugar, melted butter, olive oil, eggs, vanilla, and sour cream until well combined.
Add the wet ingredients to the dry ingredients and stir gently until just combined, being careful not to overmix.
Fold in the chocolate chips and any other add-ins you prefer.
Pour the sticky dough into the prepared pan and bake for 45-55 minutes, or until a toothpick inserted into the center comes out clean. If the top begins to brown too quickly, cover it loosely with aluminum foil.
Serve warm or allow the bread to cool for 10 minutes before transferring it to a wire rack to cool completely.
Slice and enjoy your homemade bread!
Simple Sourdough Bread Recipe (Long Fermented Version)
Start the batter 16-18 hours before you plan to bake the double chocolate chip bread to allow the active starter to ferment the flour, improving its digestibility and nutrient content.
In a large bowl, whisk together the flour, baking powder, baking soda, salt, and cocoa powder. In another bowl, mix the sourdough starter, sugar, melted butter, olive oil, eggs, vanilla, and sour cream until smooth.
Add the wet ingredients to the dry ingredients and stir gently, being careful not to overmix.
Stir in the chocolate chips and any other add-ins, then cover the mixture with a damp kitchen towel or plastic wrap.
Allow the dough to rise at room temperature for 4-6 hours. Then, for best results, place dough in the refrigerator for an additional 12-hour overnight ferment or second rise.
The next morning (after the final rise):
Preheat your oven to 350°F (175°C) and stir the dough once more with a Danish dough whisk or wooden spoon.
Pour the dough into the prepared pan and bake for 45-55 minutes, or until a toothpick comes out clean. If the top begins to over-brown, cover loosely with aluminum foil.
Serve warm or let the bread cool for 10 minutes before transferring it to a wire rack to cool completely.
Dust lightly with powdered sugar before serving.
Enjoy your delicious homemade loaf!