First, mix well flour, sugar, vanilla, salt and margarine in a mixing bowl. And then gradually add water while mixing it with hand. Continue to mix it until it does not stick.
Next, spread a quarter of the dough on a cutting board and then roll on a rolling pin until you get a very thin layer Cut app. 3cm in width.
After that roll over the cut dough to wrap the banana. Keep it aside.
Finally deep fry them with oil under medium high heat until golden brown and crunchy.