Preheat the oven to 350°F (175C/155C Fan).
Sift together flour, ½ cup of sugar and cornflour. Sift this mixture twice and set aside.
Add the egg whites to the bowl of a standing mixer fitted with a whisk attachment or a large bowl for use with electric hand whisk. Add the cream of tartar, salt and extracts. Begin beating on medium, increasing to medium-high until soft peaks form.
Begin adding the remaining 1 cup of sugar, 1 tablespoon at a time, to the beating egg whites. Once all is added, increase the mixing to high and continue until stiff peaks form.
Add the flour mixture to the egg white meringue in two or three additions, gently folding to incorporate.
Pour the mixture into an ungreased Angel Food Cake pan. Swirl a knife through this to remove excess air bubbles and bake in the lower half of the oven for 40 minutes until the top is lightly browned and appears dry.
Remove the pan from the oven and invert this so that it is left upside down in the pan to cool. As it cools, the cake will start to fall out of the pan, so you may want to place a sheet of baking paper under this.
After 1 hour of cooling, use a butter knife to loosen the cake from the pan. Run this along the edges, remove the outer ring and then also run this around the base. Carefully remove the cake and transfer to a serving plate.