Ingredients:

  • 1/2 cup (100g) all-purpose flour
  • 1/2 cup (100g) brown sugar, packed
  • 1 tbsp (8g) ground cinnamon
  • 4 tbsp (56g) unsalted butter, cold and cubed
  • 1/2 cup (120g) sourdough discard, unfed
  • 1/2 cup (120g) sour cream
  • 1/2 cup (115g) unsalted butter, melted and cooled
  • 3/4 cup (150g) granulated sugar
  • 1 large egg, room temperature
  • 1 tsp (5ml) vanilla extract
  • 2 cups (250g) all-purpose flour
  • 1 tsp (5g) baking powder
  • 1/2 tsp (3g) baking soda
  • 1/2 tsp (3g) salt

Instructions:

  1. In a medium bowl, whisk together 1/2 cup all-purpose flour, brown sugar, and cinnamon.
  2. Use a pastry cutter or fingers to work cold cubed butter into the dry ingredients until the mixture resembles coarse, sandy crumbs. Set aside in the refrigerator.
  3. Preheat oven to 375°F (190°C) and line a 12-cup standard muffin tin.
  4. In a large bowl, whisk together melted butter and granulated sugar until combined.
  5. Stir in the sourdough discard, sour cream, egg, and vanilla extract. Whisk until the mixture is velvety and smooth.
  6. Fold in the remaining flour, baking powder, baking soda, and salt using a spatula. Mix only until no streaks of flour remain.
  7. Divide the batter evenly among the 12 liners, filling them about 3/4 of the way full.
  8. Generously heap the chilled cinnamon streusel on top of each muffin, pressing down very lightly to secure it.
  9. Bake for 25–30 minutes, or until the tops are golden-brown and a toothpick inserted into the center comes out clean.
  10. Allow muffins to cool in the pan for 5 minutes before transferring them to a wire rack.