Ingredients:

  • 1 ½ cups All-Purpose Flour (for streusel)
  • ¾ cup Light Brown Sugar, packed (for streusel)
  • ¼ cup Granulated Sugar (for streusel)
  • 1 ½ teaspoons Ground Cinnamon
  • 1 teaspoon Fine Espresso or Instant Coffee Powder (optional)
  • 8 tablespoons (1 stick) Unsalted Butter, cold and cubed (for streusel)
  • ¼ teaspoon Salt (for streusel)
  • 2 cups All-Purpose Flour, sifted (for cake base)
  • 1 teaspoon Baking Powder
  • ½ teaspoon Baking Soda
  • ½ teaspoon Salt (for cake base)
  • 1 cup (2 sticks) Unsalted Butter, softened (for cake base)
  • 1 cup Granulated Sugar (for cake base)
  • 3 Large Eggs, room temperature
  • 1 teaspoon Vanilla Extract (for cake base)
  • 1 cup Sour Cream (Full Fat), room temperature
  • 1 cup Powdered Sugar (for glaze)
  • 2 – 3 tablespoons Milk or Heavy Cream (for glaze)
  • ¼ teaspoon Vanilla Extract (for glaze)

Instructions:

  1. In a medium bowl, whisk together the flour, both sugars, cinnamon, espresso powder (if using), and salt for the streusel. Add the cold, cubed butter and cut it into the dry ingredients using your fingers or a pastry blender until large, pea-sized crumbs form. Transfer the streusel to the refrigerator while you prepare the cake batter.
  2. Preheat your oven to 350°F (175°C). Grease and line a 9x9 inch pan with parchment paper, ensuring there is an overhang (a sling) for easy removal.
  3. In a separate medium bowl, whisk together the 2 cups of flour, baking powder, baking soda, and ½ teaspoon of salt. Set aside.
  4. In the large bowl of your mixer, beat the softened butter and granulated sugar (for the cake base) on medium-high speed until light, fluffy, and pale in colour (3–4 minutes).
  5. Beat in the eggs one at a time, ensuring each is fully incorporated before adding the next. Stir in the vanilla extract. Scrape down the sides of the bowl.
  6. Reduce the mixer speed to low. Add one-third of the flour mixture, followed by half of the sour cream. Repeat the flour, then the remaining sour cream, finishing with the last of the flour. Mix only until just combined. Do not overmix.
  7. Spread half of the cake batter evenly into the prepared pan. Take half of the chilled streusel and crumble it evenly over the batter layer. Gently dollop the remaining cake batter over the streusel layer and spread carefully to cover. Scatter the remaining streusel generously over the top and lightly press the crumbs into the surface.
  8. Bake for 40–45 minutes, or until a wooden skewer inserted into the centre comes out with only moist crumbs attached. Let the cake cool in the pan on a wire rack for 15 minutes before using the parchment sling to transfer it to the rack completely. Allow it to cool fully.
  9. In a small bowl, whisk the powdered sugar, vanilla, and milk/cream until smooth. Adjust the liquid amount until you reach a thick, drizzly consistency. Drizzle the glaze generously over the cooled cake. Allow the glaze to set for 5–10 minutes before slicing and serving.