# 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
# Steps to Follow:
01 - Preheat oven to 350°F. Grease a 9-inch square baking pan and line with parchment paper, leaving overhang for easy removal.
02 - In a medium bowl, combine brown sugar, flour, cardamom, cinnamon, and salt. Add cold cubed butter and rub with your fingers or pastry cutter until mixture forms clumps. Refrigerate until ready to use.
03 - In a medium bowl, whisk together flour, baking powder, baking soda, salt, and cardamom.
04 - In a large bowl, beat softened butter and granulated sugar until light and fluffy, approximately 3 minutes. Add eggs one at a time, beating well after each addition. Mix in vanilla extract.
05 - On low speed, add half of the flour mixture to the butter mixture, followed by the sour cream and milk. Add the remaining flour mixture and mix just until combined. Do not overmix.
06 - Spread batter evenly into the prepared pan. Sprinkle streusel topping evenly over the batter.
07 - Bake for 38 to 42 minutes, or until a toothpick inserted in the center comes out clean and the top is golden brown.
08 - Cool the cake in the pan for 15 minutes, then use the parchment overhang to lift it out. Cool completely on a wire rack before slicing.