1. Layer the dry ingredients in a clean quart mason jar: bread flour, cocoa powder, sugar, salt, baking soda, and chocolate chips.

2. Seal the jar and attach a gift tag with baking instructions and ingredient list.

3. When ready to bake, activate or feed your sourdough starter until bubbly.

4. Preheat the oven to 350°F (175°C) and grease a loaf pan.

5. Empty the jar mix into a large bowl and whisk together warm water, sourdough starter, oil, and egg if using.

6. Stir gently until no dry pockets remain, adding water by tablespoons if too stiff.

7. Pour batter into the prepared loaf pan and smooth the top.

8. Let the batter rest for 30 minutes if using active starter to develop flavor.

9. Bake for 45–55 minutes until a toothpick comes out with a few melted chocolate streaks.

10. Cool in the pan for 15 minutes, then remove and slice once slightly cooled.