Step 1

Start by preheating your oven to 325°F (160°C). Grease and line a 9×9-inch baking pan with parchment paper to ensure your cake lifts out easily once baked.

Step 2

In a large mixing bowl, whisk the egg yolks with the granulated sugar. Beat the mixture until it turns pale and creamy, which usually takes about 2-3 minutes. This creates the base for your cake, ensuring a light and airy texture.

Step 3

Next, add the lemon zest, freshly squeezed lemon juice, melted butter, and vanilla extract. These ingredients will infuse the cake with a delicious citrus flavor and a buttery richness. Mix until everything is well incorporated and smooth.

Step 4

In a separate bowl, sift together the all-purpose flour and salt. Slowly add these dry ingredients into the wet mixture, stirring as you go. This will prevent lumps from forming and ensure the cake batter is smooth and even.

Step 5

Gradually pour in the room-temperature milk, whisking continuously to create a slightly thin, smooth batter. The milk gives the cake its custard-like texture, so make sure it’s well combined.

Step 6

In a clean bowl, beat the egg whites until stiff peaks form. This will add the airiness that makes the cake’s top layer fluffy. Carefully fold the whipped egg whites into the lemon batter in small batches, making sure to retain as much volume as possible.

Step 7

Pour the light, airy batter into your prepared baking pan and smooth the top with a spatula. Bake for 40-45 minutes, or until the top of the cake is golden brown, and the center is just slightly jiggly. The custard layer will set during cooling.

Step 8

Once baked, remove the cake from the oven and allow it to cool completely in the pan. Dust the top with powdered sugar for a beautiful finish before slicing and serving.