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 crêpes over low heat.
6. Melt the dark chocolate.
7. Slice the banana into rounds.
8. Place the banana slices on each crêpe, cover one with chocolate and the other with Nutella (different diets, one without milk and the other without).