Separate & freeze egg whites: Separate egg yolks and whites. Place egg whites in the freezer until tiny ice crystals form (~15 mins).

Make batter base: Heat milk and butter in a double boiler (or microwave-safe bowl in 30-second bursts) until butter melts completely. Remove from heat. Sift cake flour over the mixture; whisk until smooth. Add egg yolks and whisk until combined. Set aside—keep warm (40°C/104°F) (e.g., over a double boiler) to prevent the batter from solidifying while you whip the egg whites.

Whip egg whites: In a clean, grease-free bowl, whip frozen egg whites with granulated sugar and lemon juice on medium-high speed until soft peaks form.

Combine batters: Fold ⅓ of the whipped egg whites into the yolk batter to lighten it. Gently pour the yolk mixture back into the remaining egg whites and fold until just combined(avoid overmixing).

Bake: Preheat oven to 150°C (302°F). Line a 28×28×2.6cm baking pan with parchment paper or a silicone mat. Pour the batter in and spread evenly. Bake for 30 mins, or until the surface is golden and a toothpick inserted comes out clean. Cool completely in the pan, then unmold and cut into three equal horizontal layers.

Whip cream: In a cold bowl, whip heavy cream with sugar until stiff peaks form (hold their shape when the whisk is lifted).

Layer cake: Place the first cake layer on a serving plate. Spread a thin layer of whipped cream evenly over the top. Pipe a border of whipped cream around the edges (to contain the lemon curd). Fill the center with lemon curd. Top with the second cake layer and repeat: spread whipped cream, add lemon curd, then add the third layer.

Apply a thin “crumb coat” of whipped cream over the entire cake (to trap loose crumbs). Refrigerate for 15 mins to set. Apply a final, even layer of whipped cream and smooth with an offset spatula. Chill for 30 mins to firm up.

Soak gelatin sheets in cold water for 5–7 mins until soft. Squeeze out excess water.

Heat heavy cream in a microwave-safe bowl on medium-high for 1 min (or simmer gently on the stovetop). Pour the hot cream over white chocolate chips; let sit for 2 mins. Whisk until smooth, then stir in the softened gelatin until fully dissolved. Let the glaze cool to ~35°C (95°F) (warm to the touch but not hot).

Pour the glaze evenly over the chilled cake, letting it drip down the sides. Chill for 10–15 mins to set the glaze.

Top with freshly grated lime zest. Slice with a sharp knife (wiped clean between cuts) and serve.