Ingredients:

  • 3/4 cup all-purpose flour
  • 1/2 cup granulated sugar
  • 1 tbsp ground cinnamon
  • 1/2 cup unsalted butter, cold and cubed
  • 2 cups all-purpose flour
  • 1 tbsp baking powder
  • 1/2 tsp salt
  • 1/2 cup unsalted butter, softened
  • 1 cup granulated sugar
  • 2 large eggs
  • 1 tsp vanilla extract
  • 1 cup full-fat sour cream
  • 1 1/2 cups fresh black raspberries
  • 2 tbsp cornstarch
  • 1 tbsp granulated sugar

Instructions:

  1. In a small bowl, combine flour, sugar, and cinnamon. Work the cold cubed butter into the mixture using your fingers or a fork until it forms pea-sized clumps. Set aside in the fridge.
  2. In a separate bowl, gently toss the black raspberries with cornstarch and sugar to prevent sinking.
  3. Beat the softened butter and sugar on medium-high until light and fluffy (about 3 minutes).
  4. Add eggs one at a time, beating well after each addition, then stir in the vanilla extract.
  5. Whisk together the flour, baking powder, and salt. Gradually add the dry ingredients to the butter mixture, alternating with the sour cream. Mix on low just until combined.
  6. Spread half of the batter into the greased and parchment-lined 9x9 inch baking pan. Scatter the coated black raspberries evenly over the top.
  7. Gently dollop the remaining batter over the berries and smooth it out with a spatula.
  8. Sprinkle the chilled cinnamon streusel evenly across the surface.
  9. Bake at 350°F (175°C) for 35-40 minutes.
  10. The cake is done when the top is a deep golden-brown and a toothpick inserted into the center comes out clean.