Ingredients:

  • 225g (1 cup) Unsalted butter, softened
  • 300g (1 ½ cups) Granulated white sugar
  • 3 Large eggs, room temperature
  • 240g (1 cup) Full fat sour cream
  • 325g (2 ½ cups) All purpose flour
  • 40g (½ cup) Dutch processed cocoa powder
  • 60ml (4 tbsp) Boiling water
  • 15ml (1 tbsp) Neutral oil
  • 25g (2 tbsp) Granulated sugar
  • Baking powder
  • Baking soda
  • Salt

Instructions:

  1. Preheat your oven to 350°F and grease a 9x5 inch loaf pan. Sift your flour, baking powder, baking soda, and salt into a medium bowl and set aside.
  2. Beat the 225g softened butter and 300g sugar together for 3 minutes until pale and fluffy. Add the eggs one at a time, followed by the vanilla paste, scraping the bowl frequently.
  3. Alternate adding the flour mixture and the 240g sour cream to the butter mixture. Start and end with the flour, mixing until just combined and no streaks remain.
  4. In a separate small bowl, whisk 40g cocoa powder, 60ml boiling water, 15ml oil, and 25g sugar until a smooth, glossy paste forms. Remove about 1.5 cups of the vanilla batter and stir it into the chocolate paste.
  5. Dollop large spoonfuls of vanilla batter and chocolate batter into the prepared pan in an alternating pattern. Use a knife to swirl the batters using only two or three S motions.
  6. Bake for 45 minutes until the top is golden and a skewer comes out clean. Let it rest in the pan for 15 minutes before transferring to a wire rack to cool completely.