Preheat your oven to 350°F (175°C) and grease a 9-inch x 9-inch cake pan with butter or non-stick spray.

In a medium mixing bowl, whisk together 2 cups of cake flour, ½ teaspoon baking powder, ½ teaspoon kosher salt, 1 teaspoon ground cardamom, and ¼ teaspoon ground cinnamon.

In a stand mixer, cream together 16 tablespoons of softened unsalted butter and ¼ cup of granulated sugar until sandy in texture.

Gradually add the dry ingredients while mixing on low, then add 4 tablespoons of vegetable oil, 3 large eggs, ½ cup of sour cream, and 1 tablespoon of vanilla extract.

Pour the batter into the prepared cake pan and spread it evenly.

In a small bowl, mix together ¼ cup of granulated sugar and 1 teaspoon of ground cardamom and sprinkle it over the batter.

Bake in the preheated oven for 30 minutes or until a toothpick comes out clean when inserted in the center.

Let the cake cool in the pan for about 10 minutes before transferring it to a wire rack to cool slightly before serving.