Peel and core the apples and cut them into pieces of about 2 cm, sprinkling with the lemon juice as you go so they don't brown.
Put them in a pan with the water, the sugar and the scraped vanilla (or cinnamon).
Cover and cook over low-medium heat, stirring now and then, for 15-20 minutes until the apples are completely soft and falling apart.
Crush roughly with a fork or potato masher (for a smoother version, blend with a stick blender). If it's too thin, cook uncovered for a few more minutes.
Serve lukewarm or cold, with toasted baguette or yogurt. It keeps for 4-5 days in a sealed jar in the fridge.
A Receptnaptár original recipe. Calories and protein are estimated.