Rinse, peel, core and quarter the apples. Grate them in a food processor. If you don't have a food processor simply chop them as fine as possible.
Add the apples to a heavy bottom saucepan or pot. Add vinegar, water, cinnamon stick and star anise.
Cover and cook on a low heat until the apples are slightly softened.
Add sugar and continue to cook stirring often until thick. Add ground cinnamon and vanilla.
When it thickens test by swiping the bottom of the pot with a spatula. It should leave a trail behind the spatula. (Check step by step photos in the post)
Do a final test by dropping a spoonful of apple jam on a cold plate. It should not spread and must retain its shape. The other way to check is to cool it slightly and run your finger in the center of the jam. It should leave a space showing the line.
Cool apple jam completely and store in a clean air tight dry glass jar. It lasts for few months in the refrigerator. Spread it on toasts, parathas or fresh bread.