Preheat the oven to 350°F (180°C).

Peel and core the apples. Cut them into small cubes.

In a saucepan, sauté the apples with the butter and vanilla sugar.

Butter a tart pan and layer the phyllo sheets inside, then add the apples.

Bake for 15 minutes.

Meanwhile, beat the egg whites with the cinnamon until stiff peaks form.

Remove the tart from the oven and spread the beaten egg whites on top.

Return to the oven for 10-15 minutes, until the egg whites are golden.

Serve warm or cold.