Preheat the oven to 170 °C. Grease and line a rectangular baking dish.

Whisk egg yolks with most of the sugar until pale and thick, then mix in vanilla.

Whip egg whites with salt until soft peaks form, then gradually add remaining sugar and whisk to glossy peaks.

Fold flour and baking powder into the yolk mixture, then gently fold in the egg whites.

Pour batter into the prepared dish and bake until golden and a skewer comes out clean.

Cool slightly, then pierce the cake all over and slowly pour over the mixed three milks.

Whip cream with vanilla until soft peaks form and spread evenly over the soaked cake.