01 -
Preheat oven to 163°C. Grease an 8-inch square baking dish or line with parchment paper.
02 -
Beat the egg whites in a mixer until stiff peaks form. Transfer to a separate bowl and set aside.
03 -
Beat egg yolks with sugar until light and fluffy. Add melted butter and vanilla extract, continuing to beat for 1-2 minutes until well incorporated.
04 -
Incorporate flour into the batter, mixing until smooth and well combined.
05 -
Mix in lemon juice and lemon zest. Gradually add the warmed milk, beating until all ingredients are thoroughly combined.
06 -
Gently fold in the whipped egg whites one-third at a time using a spatula or whisk. The batter should still contain visible white streaks when complete.
07 -
Pour batter into the prepared baking dish and bake for 40-70 minutes, until the top is lightly golden and the cake feels firm to the touch. Baking time may vary significantly depending on your oven.
08 -
Allow cake to cool completely. Dust with powdered sugar, then cut into squares before serving.