# What You'll Need:
→ Streusel Topping
01 - 1/2 cup packed light brown sugar
02 - 1/3 cup all-purpose flour
03 - 1 teaspoon ground cardamom
04 - 1/4 teaspoon ground cinnamon
05 - 1/8 teaspoon fine sea salt
06 - 3 tablespoons unsalted butter, cold and cubed
→ Cake Batter
07 - 1 1/2 cups all-purpose flour
08 - 1 1/2 teaspoons baking powder
09 - 1/2 teaspoon baking soda
10 - 1/2 teaspoon fine sea salt
11 - 1 teaspoon ground cardamom
12 - 1/2 cup unsalted butter, softened
13 - 3/4 cup granulated sugar
14 - 2 large eggs, room temperature
15 - 2 teaspoons pure vanilla extract
16 - 2/3 cup sour cream
17 - 1/4 cup whole milk
# How-To Steps:
01 - Preheat oven to 350°F. Grease a 9-inch square baking pan and line with parchment paper, leaving overhang on sides for easy removal.
02 - In a medium bowl, combine brown sugar, flour, cardamom, cinnamon, and salt. Add cold cubed butter and rub with fingers or pastry cutter until mixture forms coarse clumps. Refrigerate until needed.
03 - In a medium bowl, whisk together flour, baking powder, baking soda, salt, and cardamom. Set aside.
04 - In a large bowl, beat softened butter and granulated sugar with an electric mixer until light and fluffy, approximately 3 minutes.
05 - Add eggs one at a time to the butter mixture, beating well after each addition. Mix in vanilla extract until fully combined.
06 - On low speed, add half of the flour mixture to the butter mixture, followed by sour cream and milk. Add remaining flour mixture and mix just until combined, avoiding overmixing.
07 - Spread batter evenly into the prepared pan. Sprinkle streusel topping uniformly over the batter surface.
08 - Bake for 38 to 42 minutes until a toothpick inserted in the center comes out clean and the top is golden brown.
09 - Allow cake to cool in the pan for 15 minutes. Use parchment overhang to lift cake from pan and transfer to a wire rack. Cool completely before slicing.
