In a large bowl, cream the sugar with the butter. Then add the egg-white, beat until homogeneous. Finally add the flour, combine well.
With the help of a spatula or a palette knife, spread very thinly the dough over a silicon baking mat (or baking paper). Put in a preheated oven (medium heat) for about 8 minutes.
Remove from the oven and allow to cool down for 1 minute. Then crush it in small pieces. Leave to cool down completely. The pailleté feuilletine fears humidity so keep it in a hermetic container. Do not combine into moist mixtures or else it will lose its crispness. Usually it is mixed with praline paste, chocolate, cocoa butter to create a crispy layer into cakes…
If you notice that it lost its crispness even if preserved in a hermetic box, then bake again for 5 minutes before to use.