Quarter and core the apples leaving the skin on for extra fibres. Then, add them to a food processor along with water and fresh spinach. Pulse until the apples are completely mashed.
Now, tip in the soy yogurt, oat flakes, and almond butter. Whizz until the ingredients are well incorporated and the oats are finely ground.
At this point, you can add the spirulina powder, if using it - it will give the smoothie a deep green tone and boost its nutrients. Finally, pour the apple smoothie in serving glasses or store it away in the fridge in a jar or air-tight bottle.
