Step 1

Preheat your oven to 350°F (175°C). Generously grease and flour a 9×9-inch (or similar size) baking dish.

Step 2

In a mixing bowl, prepare the streusel topping: combine 1/2 cup flour, 1/2 cup brown sugar, and 1/2 teaspoon cinnamon. Add 1/4 cup softened butter and use a fork or your fingers to work it into coarse crumbs. Set aside.

Step 3

In a large bowl, cream together 1/2 cup butter and 1 cup granulated sugar until light and fluffy.

Step 4

Beat in the eggs, one at a time, mixing well after each addition. Stir in 1 teaspoon vanilla extract.

Step 5

In a separate bowl, whisk together 2 cups flour, 2 teaspoons baking powder, 1/2 teaspoon baking soda, and 1/2 teaspoon salt.

Step 6

Add the dry ingredients to the creamed mixture alternately with 1 cup sour cream, beginning and ending with the flour mixture. Mix until just combined—do not overmix.

Step 7

Spread half the cake batter evenly in the prepared baking dish. Sprinkle half of the streusel mixture over the batter. Repeat with the remaining batter and sprinkle the rest of the streusel on top.

Step 8

Bake for 35-40 minutes, or until a toothpick inserted into the center comes out clean and the top is golden brown.

Step 9

Let cool for at least 15 minutes before slicing. Serve warm for the ultimate experience!