-
1
Heat the oven to 230 °C and line two baking sheets with parchment. Separate the eggs, placing yolks and whites in separate bowls, then beat the yolks with the caster sugar until the mixture is pale, thick, and falls from the whisk in a continuous, slowly dissolving ribbon — the sabayon stage — because only at this point has enough air been beaten in to give the finished biscuit its characteristic light, open crumb. Add the colorant and stir until the hue is uniformly pale pink.
-
2
In a separate, scrupulously clean bowl, beat the egg whites to firm, glossy peaks, then fold them into the yolk-sugar mixture in two additions, working gently so the foam stays alive and the batter retains the volume that will carry the biscuits upright during baking. Sift the flour over the surface and fold in with deliberate, sweeping strokes until no dry streaks remain; the batter should fall from the spatula in a slow, heavy ribbon.
-
3
Transfer the batter to a piping bag fitted with a plain 1.5 cm nozzle and pipe finger shapes approximately 8–9 cm long onto the prepared sheets, spacing them 3 cm apart so they have room to rise without merging. Dust generously and evenly with icing sugar, which will melt and then set during baking to form the distinctive white, lightly crystalline crust; the surface should appear frosted and white.
-
4
Bake at 230 °C for 5–7 minutes — the biscuits must be just set and risen, surface dry to the touch, with no browning whatsoever, because any colour at this stage destroys the pale pink irreversibly and no second bake will recover it. Remove from the oven and allow to cool completely on the sheets before proceeding.
-
5
Reduce the oven to 110 °C, within the 100–120 °C range, and return the cooled biscuits for 30–40 minutes so moisture driven from the centre can escape gradually without the outside darkening or the icing-sugar crust cracking. This is where the dish lives or dies: press one gently at the base — it must feel rigid and bone-dry with no soft or yielding core, because any residual moisture will cause rapid staling rather than the months-long crispness that defines the biscuit rose.
-
6
Remove from the oven and cool on a wire rack; the biscuits should be shatteringly crisp throughout, a pale, even pink with a white icing-sugar crust. Transfer immediately to an airtight tin, as they begin drawing in atmospheric moisture at once and will soften within the hour if left exposed.