Ingredients:

  • 1 ½ cups All-Purpose Flour (for streusel)
  • ¾ cup Light Brown Sugar (packed, for streusel)
  • 1 ½ teaspoons Ground Cinnamon (for streusel)
  • ½ cup (1 stick) chilled Unsalted Butter, cubed (for streusel)
  • 2 ½ cups All-Purpose Flour (for cake batter)
  • 1 ½ teaspoons Baking Powder
  • ½ teaspoon Baking Soda
  • ½ teaspoon Salt
  • 1 cup (2 sticks) Unsalted Butter, room temperature (for batter)
  • 1 ¾ cups Granulated Sugar
  • 3 large Eggs, room temperature
  • 1 ½ teaspoons Vanilla Extract
  • 1 ½ cups Full-Fat Sour Cream, room temperature
  • 1 cup Powdered Sugar (for optional glaze)
  • 2-3 tablespoons Milk or Cream (for optional glaze)

Instructions:

  1. Preheat oven to 350°F (175°C). Grease and lightly flour a 9x13 inch baking dish or a 10-inch tube/Bundt pan.
  2. Make the Streusel: In a medium bowl, whisk together the 1 ½ cups flour, brown sugar, and cinnamon. Cut in the cold, cubed butter using a pastry blender or fingertips until the mixture resembles coarse crumbs. Set aside in the refrigerator.
  3. Combine Dry Ingredients for Cake: In a separate bowl, whisk together the 2 ½ cups flour, baking powder, baking soda, and salt. Set aside.
  4. Cream Butter and Sugar: In a large mixing bowl, beat the room-temperature butter and granulated sugar together until light and fluffy (about 3–4 minutes).
  5. Incorporate Eggs and Vanilla: Beat in the eggs one at a time, ensuring each is fully incorporated before adding the next. Mix in the vanilla extract.
  6. Alternate Wet and Dry: Add the dry ingredients mixture to the butter mixture in three additions, alternating with the sour cream (begin and end with dry ingredients). Mix only until just combined—do not overmix.
  7. Assemble the Cake: Pour half of the batter into the prepared pan. Sprinkle half of the chilled streusel evenly over the batter. Top with the remaining batter, then sprinkle the rest of the streusel evenly on top.
  8. Bake for 45–55 minutes, or until a wooden skewer inserted near the center comes out clean (it's okay if it hits melted butter from the streusel, but there should be no wet batter).
  9. Cool the cake in the pan for 15 minutes before carefully inverting onto a wire rack to cool completely.
  10. Glaze (Optional): Once fully cooled, whisk the powdered sugar with 2 tablespoons of milk/cream until smooth, adding more liquid gradually if needed to reach a drizzling consistency. Drizzle over the top before serving.