This recipe isn't as easy as it sounds, the difficulty is getting the biscuits to bulge nicely rather than being (too) flat. The key to success lies in steps 3
where you need to incorporate the meringue very carefully
to keep the light side of the preparation. Take great care in this delicate operation.
The small history said that those biscuits was created in the 18th
century by the famous chef Antonin Carème, at this time chef of Prince of Talleyrand. The prince love to dip a biscuit in his glass of Porto wine every evening, so Carème make this long biscuits for him (I love those pretty stories).
According to Mado, in Quebec these biscuits are called "Doigts de dames" (ladies' fingers), which is rather more poetic.