Ingredients:
- * 1/2 cup unsalted butter softened
- * 1 cup sugar
- * 2 teaspoon vanilla
- * 2 teaspoon baking powder
- * 2/3 cup unsweetened cocoa powder
- * 1/2 teaspoon salt
- * 2 egg
- * 3/4 cup milk
- * 1/3 cup sour cream
- * 2 cup all purpose flour
- * 1 1/2 cup chocolate chip