Steps
- Preheat the oven to 350°F / 175°C. Line the base of an ungreased 9in / 23cm springform pan with parchment.
- Whisk 6 large room-temperature eggs on high speed for 1 minute. Gradually add 1 cup of sugar and whisk for 8-10 minutes, until thick ribbons hold briefly on the surface.
- Peel, core, and quarter 675g of Granny Smith apples, then cut into ¼in / 5mm slices. Reserve a small portion to scatter over the top.
- Whisk 1⅓ cups of all-purpose flour with ½ teaspoon of baking powder. Sift into the eggs in 3 additions, folding gently until no flour remains. Fold in 1 teaspoon of vanilla extract.
- Fold in the apples and spread in the pan without tapping it. Scatter the reserved apple on top and bake for 50-55 minutes, until golden.
- Cool in the pan for 15 minutes. Loosen the edges with a thin knife, remove the pan sides, and cool completely.