- With the rack in the middle position, preheat the oven to 165 °C (325 °F).
- In a large saucepan, bring maple syrup to a boil over medium heat. Cook until it reaches 120 °C (250 °F), about 15 minutes.
- Meanwhile, in a large bowl, beat egg whites with an electric mixer on medium speed until soft peaks form. When syrup reaches the desired temperature, reduce mixer speed and gradually drizzle in egg whites, beating constantly, until stiff peaks form.
- Sift flour over meringue and gently fold with a whisk until smooth, but maintains its volume.
- Spoon into an ungreased 25-cm (10-inch) chiffon cake pan. Bake for about 45 to 50 minutes or until the surface of the cake springs back when pressed.
- Immediately place cake pan upside down on the neck of a bottle and let cool for about 3 hours or until completely cooled. Run a thin knife around the edges of the cake and the pan and unmould. Keeps two or three days under a lid.
In baked goods, we often prefer amber maple syrup to light syrup because its flavour is more intense.