Ingredients:

  • 1/2 cup (65g) all-purpose flour
  • 1/3 cup (65g) light brown sugar, packed
  • 1 tsp (2g) ground cinnamon
  • 4 tbsp (55g) unsalted butter, cold and cubed
  • 2 cups (250g) all-purpose flour
  • 3/4 cup (150g) light brown sugar, packed
  • 2 tsp (10g) baking powder
  • 1/2 tsp (3g) baking soda
  • 1/2 tsp (3g) salt
  • 1/2 cup (120g) sour cream, room temperature
  • 1/2 cup (120ml) vegetable oil
  • 2 large eggs, room temperature
  • 1 tsp (5ml) vanilla extract
  • 1 1/2 cups (225g) fresh rhubarb, diced into 1/4-inch pieces

Instructions:

  1. In a small bowl, whisk together 1/2 cup flour, 1/3 cup brown sugar, and 1 tsp cinnamon.
  2. Use a pastry cutter or fork to work the cold cubed butter into the crumble mixture until it resembles coarse crumbs.
  3. Set the crumble aside in the refrigerator to keep the butter firm.
  4. Preheat oven to 375°F (190°C) and line a 12-cup muffin tin with paper liners.
  5. In a medium bowl, whisk together 2 cups flour, 2 tsp baking powder, 1/2 tsp baking soda, and 1/2 tsp salt.
  6. In a large bowl, beat eggs and 3/4 cup brown sugar until smooth, then whisk in sour cream, oil, and vanilla until velvety.
  7. Pour the dry ingredients into the wet mixture and stir with a spatula until just combined.
  8. Gently fold in the diced rhubarb pieces using a spatula until evenly distributed.
  9. Divide batter into muffin tin and top with the chilled cinnamon crumble.
  10. Bake for 20 minutes or until a toothpick inserted into the center comes out clean.