Directions

1. Preheat oven to 350 degrees F and place the rack in the center of the oven. Spray an 8 inch square pan with a nonstick vegetable cooking spray.
   
2. In the bowl with a hand mixer, beat the sugar and butter until smooth. Beat in the vanilla extract and egg.
   
3. In a small bowl, whisk together the flour, cocoa powder, and baking powder. Fold this flour mixture into the sugar and butter. Stir in the sour cream.
   
4. Pour into the prepared pan and smooth the top. Bake for about 15 - 20 minutes, or until the edges start to pull away from the sides of the pan and the center of the brownies is still slightly soft. (Do not over bake or the brownies will be too dry.)
   
5. Remove from oven and place on a wire rack to cool. These brownies can be frozen for a month or two.