1/2 cup all-purpose flour
2/3 cup unsweetened cocoa powder
1/2 tsp baking soda
3/4 tsp baking powder
1/2 tsp salt
1 cup buttermilk
1 cup + 2 tbsp sugar
1 egg or 1/4 cup egg substitute
2 tsp vanilla
1 oz unsweetened chocolate, melted
1 envelope whipped topping mix (half of a 2.6-oz box)
1/2 cup low-fat milk
Preheat oven to 350 degrees. Line an 8-inch baking pan with enough foil to hang over the sides. Coat the foil well with nonstick cooking spray. Set aside.
In a small bowl, combine the flour, half the cocoa powder, the baking powder, baking soda, and salt; set aside.
In a medium mixing bowl, using an electric mixer at low speed, combine the buttermilk, one cup of the sugar, egg, and half the vanilla. Beat in the flour mixture then the melted chocolate. Pour into the prepared baking pan and bake at 350 degrees for 35 minutes or until a wooden toothpick inserted in the center comes out clean. Cool in the pan for 10 minutes. Remove from the pan and cool completely on a wire rack.
With mixer on low speed, combine the topping mix, remaining cocoa and remaining sugar. Add the milk and the remaining vanilla. Increase speed to medium and beat until fluffy. Spread over the brownies.