Spoon out the batter in a donut pan, filling each will 3/4. Bake in the preheated to 180 degrees C (360 degrees F) for about 12-15 minutes. Thanks to the apple and juice, it will be extra moist and require longer baking than regular cake donuts.
Separately, combine the grated apple, sugar, egg, egg white, olive oil, and milk. Combine the dry and wet ingredients. Mix just until well incorporated.