- 2⅓ cups (300 g/10.6) flour – regular all-purpose (see note 1 if you want to use cake flour)
- ¼ cup (25 g) cornstarch
- 2½ tsp baking powder
- ½ tsp salt – omit if using salted butter
- 1 cup (240 ml) milk – room temperature
- 1 tsp white vinegar
- Six large egg whites – room temperature, size seven eggs
- ½ cup (113 g/ 4Oz) unsalted butter – room temperature
- ½ cup (110 ml) unflavoured vegetable oil – I use canola
- 1⅔ cups (333 g/ 11.7Oz) white granulated sugar
- 1¼ tbsp vanilla essence/extract
