Mix the sugar and eggs in a copper bowl, place over a gentle heat so that it becomes slightly warm and whisk until the mixture reaches the ribbon stage. Remove from the heat and continue to whisk until it is cold. Now add the chosen flavouring, the flour and the melted butter from which the liquid and sediment has been removed. The flour should be folded in lightly and the butter added in a thin stream so that the mixture does not become heavy.
According to requirements the mixture can be baked in various moulds or spread on a buttered and floured tray.