Ingredients:

  • 1/2 cup (65g) all-purpose flour
  • 1/2 cup (100g) brown sugar, packed
  • 4 tbsp (55g) unsalted butter, cold and cubed
  • 1 tsp (2g) ground cinnamon
  • 2 cups (300g) fresh rhubarb, chopped into 1/2 inch pieces
  • 1/4 cup (50g) granulated sugar
  • 1 tbsp (8g) cornstarch
  • 2 cups (250g) all-purpose flour
  • 1 tsp (4g) baking powder
  • 1/2 tsp (3g) baking soda
  • 1/2 tsp (3g) salt
  • 1/2 cup (115g) unsalted butter, softened
  • 1 cup (200g) granulated sugar
  • 2 large (100g) eggs, room temperature
  • 1 tsp (5ml) vanilla extract
  • 1 cup (240g) full-fat sour cream

Instructions:

  1. Preheat the oven to 350°F (175°C). Grease a 9x9 inch baking pan and line it with parchment paper.
  2. In a medium bowl, toss the chopped rhubarb with 1/4 cup granulated sugar and cornstarch until evenly coated; set aside.
  3. In a small bowl, combine 1/2 cup all-purpose flour, brown sugar, and cinnamon. Use fingers or a fork to rub in cold cubed butter until the mixture resembles coarse crumbs. Refrigerate until needed.
  4. In a large bowl, cream together softened butter and 1 cup granulated sugar until pale and fluffy. Beat in eggs one at a time, then stir in vanilla extract.
  5. Whisk together 2 cups all-purpose flour, baking powder, baking soda, and salt. Gradually add the dry ingredients to the butter mixture, alternating with the sour cream, mixing until just combined.
  6. Pour the batter into the prepared pan and spread the rhubarb mixture evenly over the top. Sprinkle the chilled cinnamon streusel over the fruit.
  7. Bake for 50 minutes or until a toothpick inserted into the center comes out clean. Allow to cool before slicing.