vegetable cooking spray

3/4	cup (105 g) unbleached all-purpose flour

1/2	cup (128 g) natural cocoa powder

1	teaspoon (5 ml) baking powder

1/2	teaspoon (1.25 ml) baking soda

1	banana, 3 1/2 ounces (105 g) after peeling

6	tablespoons (65 g) light brown sugar

6	tablespoons (7.5 g) spoonable brown sugar substitute

1/2	cup (120 ml) unsweetened apple juice

1	teaspoon (5 ml) pure vanilla extract

1/2	teaspoon (2,5 ml) chocolate extract

4	large egg whites, at temperature

1/2	teaspoon (2.5 ml) salt

1/4	cup (60 g) chocolate chips

1. Preheat oven to 350°F (180°C), Gas Mark 4. Lightly coat a 8-inch (20 cm) square baking pan with cooking spray. In a bowl, combine the flour, cocoa, baking powder, and baking soda.
2. In a blender or food processor, combine the banana, brown sugar, apple juice, and vanilla and chocolate extracts; process until smooth. Using a rubber spatula, fold into the dry ingredients.
3. In the bowl of an electric mixer set on medium-high speed, beat the egg whites and salt until foamy. Increase the speed to high and beat until soft peaks form. Fold half of the egg whites into the batter. When incorporated, fold in remaining whites just until incorporated. (There may be a few specks of white still showing.)
4. Scrape into the pan and spread evenly. Bake in center of oven for 30 to 35 minutes, until brownie springs back when gently pressed in the center. Cool in the pan on a rack.
5. Cut into 12 squares. Heat chocolate chips in a 2-cup 480 ml) glass measuring cup in the microwave for about 30 seconds. Stir until chocolate is melted. Drizzle a little of the chocolate over each brownie.