Step 1: Prep Your Ingredients - Begin by ensuring your eggs are at room temperature. Separate the egg yolks from the whites and place them in separate bowls.
Step 2: Mix the Wet Ingredients - In a large mixing bowl, combine the egg yolks, sugar, melted butter, and vanilla extract. Whisk these ingredients together until fully combined and slightly creamy.
Step 3: Add the Dry Ingredients - Sift in the all-purpose flour, and continue mixing until no lumps remain. Slowly add the freshly squeezed lemon juice and lemon zest, stirring well to incorporate.
Step 4: Incorporate the Milk - Gradually pour in the lukewarm milk, mixing until the batter is smooth and well combined.
Step 5: Whip the Egg Whites - In another bowl, use an electric mixer to whip the egg whites until they form stiff peaks.
Step 6: Fold in the Egg Whites - Gently fold the whipped egg whites into the lemon batter to create the cake's magical layers.
Step 7: Bake the Cake - Pour the batter into the prepared baking pan and spread it evenly. Bake in the preheated oven for 40 to 50 minutes, or until the top is golden and a toothpick comes out clean.
Step 8: Cool and Dust - Allow the cake to cool completely in the pan and dust the top with powdered sugar before serving.