1. In a bowl put the sugar, oil and lemon zest; mix well.
2. Add the lemon juice, water and flour; mix until completely integrated.
3. Add the poppy seeds and mix again.
4. Transfer the mixture to a greased pan and bake over low heat for 1 hour. Check for doneness and, if necessary, leave for a couple more minutes.
5. Beat the confectioners' sugar with a little lemon juice.
6. Remove the pudding from the oven and pour the topping over the oven.