Reserve one and a half cups of milk and mix it with the flour and cornstarch.

Heat the remaining milk with the vanilla, zest, and sugar until almost boiling. Once heated, add the cold mixture of cornstarch and flour, stirring constantly and reducing the heat slightly until it thickens.

Once thickened, add the beaten eggs and stir quickly until incorporated.

Finally, add the margarine (I often skip the margarine, and it turns out just as nice). Let it cool completely, then refrigerate.

Beat the ingredients in a mixer until they thicken.

Grease a baking pan with a little margarine, place the pastry sheet on top, and prick it with a fork.

Bake at 350°F (180°C) for about 20 minutes (until golden). Do the same for the other sheet.

Mix half of the whipped cream with the cream using a whisk until smooth (even if it seems like the cream will spoil, you'll see it becomes fluffier as you mix).

Place one pastry sheet in a Pyrex dish, pressing it slightly with your hand and reserving some crumbs for decoration. Spread 3/4 of the cream on top, place the other sheet on top, and spread the remaining cream and whipped cream over it.

Finally, sprinkle the reserved crumbs and powdered sugar on top!