Start by boiling 1.5 litres of water. Once the water has boiled, set it aside and let it cool completely.
Meanwhile, in a blender jar, chop and add 2 apples with 3 tbsp of the cooled water and blend them to form a smooth purée.
Take a big airtight jar which is completely clean and dry and add sugar, apple purée, water and cinnamon stick.
Give all this a good mix and make sure the sugar is fully dissolved.
Keep the jar aside for 3 days/72 hours in a warm and dark space, preferably in a cabinet away from direct sunlight.
Mix it using a clean and dry ladle once a day.
After 3 days, strain the liquid and pour it in a swing top glass bottle, which should also be completely clean and dry.
Keep the bottle in a cool and dark space for 2-3 days. Make sure to burp the bottle every day, which means to open the bottle once a day and let the trapped gases release.
Refrigerate the drink on the last day to slow down the fermentation process and serve it chilled.
Recipe by Bake with Shivesh at https://bakewithshivesh.com/appy-fizz/