Preheat the oven to 350 degrees F. Grease a 9-inch by 9-inch baking pan and keep it ready.
In a large bowl, whisk together flour, baking powder, baking soda, salt, cinnamon powder, sugar, and brown sugar.
2 cup All purpose flour, ½ teaspoon Baking soda, 1 ½ teaspoon Baking powder, ½ teaspoon Salt, ½ teaspoon Cinnamon powder, ⅔ cup Sugar, ⅓ cup Brown sugar
Add vegetable oil, sour cream, egg, and vanilla extract, and using an electric beater, beat until it is smooth. Do not overmix.
⅓ cup Vegetable oil, ¾ cup Sour cream, 2 Eggs, 2 teaspoon Vanilla extract
Pour this batter into the baking pan. Gently tap the baking pan against the work surface to remove any trapped air pockets.
Sprinkle caramelized apples on top of this.