To begin, preheat your oven to 180°C (350°F) and grease a square 8-inch baking tin with butter or non-stick spray. In a large bowl, whisk together the eggs and sugar until the mixture becomes pale and fluffy, about 2-3 minutes. This step ensures the sponge cake will be light and airy, a perfect base for the lamingtons.

Next, slowly add the melted butter, milk, and vanilla extract to the egg mixture, continuing to whisk until combined. The key here is to gradually incorporate the wet ingredients to maintain the lightness of the batter. Stirring too quickly or aggressively can deflate the mixture, leading to a denser cake.

Sift the self-raising flour into the wet mixture, folding it in gently with a spatula. Be careful not to overmix; you want just enough stirring to combine the ingredients without losing the air you've already incorporated. This ensures the cake remains soft and spongy.

Pour the batter into the prepared baking tin, smoothing the surface evenly with a spatula. Bake for 20-25 minutes, or until a toothpick inserted into the centre comes out clean. The cake should be golden brown and spring back when lightly pressed. Let the cake cool in the tin for about 10 minutes before transferring it to a wire rack to cool completely.

Once the sponge cake has cooled, cut it into 16 even squares. For best results, refrigerate the cake squares for 30 minutes to firm up. This step makes the cake easier to handle when dipping it in the icing, preventing it from crumbling.

To prepare the chocolate icing, sift the powdered sugar and cocoa powder into a medium bowl. Gradually whisk in the milk and melted butter until the mixture is smooth and slightly thick. The icing should be thick enough to coat the cake but still fluid enough for dipping.

Place the desiccated coconut in a shallow dish. Take each cake square, and using a fork or your hands, dip it into the chocolate icing, ensuring all sides are well coated. Allow any excess icing to drip off before rolling the square in the coconut. Make sure the cake is evenly covered with coconut before placing it on a wire rack to set.

Once all the lamingtons are coated, let them sit for at least 15 minutes to allow the icing to firm up. Serve the lamingtons on a platter, optionally garnished with fresh berries or a dollop of whipped cream for an extra touch. Lamingtons are best enjoyed with a cup of tea or coffee, allowing their light sponge, rich chocolate, and coconut textures to shine. Enjoy this Australian dessert, bringing a touch of tradition and sweetness to your table.