1. Put the flour in a bowl and make a well.
2. Place the whole eggs, sugar, and margarine in the well.
3. Gently mix with a whisk while gradually adding the milk. The resulting batter should have a slightly thick liquid consistency.
4. Flavor with rum.
5. Heat a non-stick pan and lightly oil it. Pour a ladle of batter into the pan, spread it out, and wait for it to cook on one side before flipping it. Cook all the pancakes over low heat. Keep them warm.
6. Peel the apples and cut them into thin slices.
7. In an ovenproof dish, place the apple slices, ground hazelnuts, vanilla sugar, and 3 tablespoons of water.
8. Cover with aluminum foil and bake for 15 minutes at 180°C.
9. Once the apple mixture is cooked, place it on the pancakes and fold or roll them according to preference.
10. Reheat for either 5 minutes in the oven at 180°C or 2 minutes in the microwave on maximum power.