Cook down the purée: Put the raspberries, sugar, and water in a saucepan, cover, and cook over medium-low heat for 5 to 8 minutes until the berries completely break down. Uncover and keep cooking 5 minutes more, stirring, until the mixture turns thick and syrupy.

Strain it smooth: Blend the purée until completely smooth, then push it through a fine-mesh sieve with the back of a spoon to remove every seed. Measure out 6 tbsp for the soufflé base and keep the rest warm in a small pan for serving alongside.

Start the pastry cream: Heat the milk in a saucepan until it just begins to simmer around the edges. In a bowl, whisk the egg yolks, sugar, cornstarch, and vanilla until pale and smooth. Pour in the hot milk a little at a time, whisking constantly, so the yolks warm up without scrambling.

Thicken and chill: Pour the mixture back into the pan and whisk over medium heat until it turns thick and creamy, 3 to 4 minutes. Transfer to a bowl, press plastic wrap directly onto the surface (this stops a skin forming), and chill at least 30 minutes. An ice bath gets you there in about 10.

Butter the ramekins twice: Brush four 6-oz ramekins with softened butter using firm upward vertical strokes — this trains the soufflé to climb straight. Chill 5 minutes, then brush a second coat over the first. This double coat is the insurance policy for a tall, even rise.

Add the chocolate lining: Sprinkle a spoonful of finely shaved dark chocolate into each chilled ramekin, roll it to coat the inside evenly, and tap out the excess. Chill the lined ramekins until you are ready to fill them.

Heat the oven and mix the base: Preheat the oven to 375°F and set a baking sheet inside to heat up. In a large bowl, whisk the 6 tbsp of raspberry purée into the 2 1/2 tbsp of chilled pastry cream until completely smooth and evenly pink.

Whip the whites: In a spotlessly clean, dry bowl, whisk the egg whites until foamy, then add the lemon juice. Once the volume has visibly grown, sprinkle in the sugar gradually while whisking to stiff, glossy peaks that hold their shape when you lift the whisk.

Fold in two stages: Whisk one-third of the whites into the raspberry base fairly firmly to loosen it — this sacrifice batch can take the beating. Then gently fold in the remaining whites in two additions, cutting down the center and sweeping around the bowl, stopping the moment no white streaks remain.

Fill and clean the rims: Spoon the mixture into the prepared ramekins, filling each right to the top. Tap the ramekins lightly on the counter once, level the tops with a flat knife, then run your thumb around the inside edge of each rim — this clean gap lets the soufflé rise straight instead of catching and tilting.

Bake fast: Set the ramekins on the hot baking sheet and bake 10 to 12 minutes, until well risen, golden on top, and firm at the edges with the faintest jiggle in the center. Do not open the oven door before 10 minutes or you will lose the lift.

Serve immediately: Dust the tops generously with icing sugar. For the dramatic table finish, poke two small holes in the center of each soufflé with a spoon and pour in a little of the warm reserved raspberry purée. Carry to the table at once — a soufflé waits for no one.