Prepare the Oven: Begin by setting your oven to a warm 350°F (175°C) to create the perfect baking environment. Lightly grease an 8x8-inch baking dish or small cake pan.

Prepare the Batter Base: In a large mixing bowl, combine the melted butter and granulated sugar, mixing until smooth. Add the egg yolks one at a time, whisking after each addition until well combined.

Add the Lemon and Flour: Stir in the flour, grated lemon zest, and lemon juice, mixing until you have a smooth batter.

Incorporate the Milk: Gradually add the milk, stirring continuously until the batter is smooth and well mixed. Set aside.

Beat the Egg Whites: In a separate, clean mixing bowl, beat the egg whites until they form soft peaks. Gently fold the beaten egg whites into the lemon batter, being careful not to overmix to keep the batter light and airy.

Bake the Cake: Gently transfer the batter into the lined baking dish. For a moist finish, nestle the dish inside a larger pan, then pour hot water into the outer pan until it reaches about halfway up the sides of the baking dish. This method will ensure a custard-like consistency. Bake in the preheated oven for 45 to 50 minutes, or until the surface turns a lovely golden brown and feels firm to the touch.

Cool and Dust: Allow the cake to cool slightly, then dust with confectioners’ sugar before serving.

Serve Warm or Chilled: This pudding cake can be enjoyed warm for a soft, custardy texture or chilled for a more set consistency. Serve as is, or with a dollop of whipped cream or a few fresh berries.