Preheat your oven to 180C / 355F (fan off), 160C / 320F (fan on). Line two large baking sheets with baking paper and dust generously with powdered sugar. Set aside.
Combine dry ingredients - Sift your flour and corn flour together in a medium bowl. Use a whisk to combine. Set aside.
Make meringue - To a separate, and very clean bow (see notes) add your egg whites and whip on medium speed using an electric hand mixer. Once you reach soft peaks, add the sugar 1 tsp at a time, while the mix is on high speed. Once all the sugar has been added continue whipping for 1-2 minutes until you reach stiff glossy peaks.
Add remaining ingredients - Add the egg yolks and gently fold through using a hand whisk. Once combined, sift in the dry ingredients and use a spatula to gently fold through so you don’t deflate your mixture. Fold gently and take care to scrape from the bottom which is where all the dry ingredients like to hide. Once you can see no dry ingredients the batter is ready!
Scoop out rounds of batter - Use two large spoons or an ice cream scoop about 1 tbsp in capacity to scoop rounds of batter onto your baking tray spacing them out about 2 inches apart as they will spread. If you'd prefer a flatter shape, gently spread each batter round with the back of a spoon before baking.
Bake - Bake in the middle rack for 3 1/2 minutes, then turn around and bake for another 3 1/2 minutes. They’ll be done when they’re lightly golden in color and spring back when lightly touched. Allow to cool on the baking trays before taking off.