Preheat the oven to 180°C. Spray 2 baking trays with cooking spray; put aside. Place the oats in a small baking dish and toast in the oven, stirring occasionally, for 7 minutes. Transfer to a large bowl to cool.
Add the apples, almonds and a pinch of salt, stirring to combine. Whisk the egg whites until stiff peaks form, then gradually add the sugar, whisking until dissolved. Whisk in the vanilla essence. Fold into the oats and fruit.
Use a tablespoon to drop the mixture onto the prepared baking trays. Bake for 18 minutes or until golden brown and slightly firm. Cool for 5 minutes on the trays, then transfer the macaroons to a wire rack to cool completely.