In a clean bowl, whip egg whites until soft peaks form. Gradually add the remaining sugar and continue whipping until stiff, glossy peaks appear. This aeration gives the sponge its absorbent yet stable structure.

Fold the dry ingredients into the yolk mixture in small batches. Add whipped egg whites in stages, folding gently from the bottom up. Avoid overmixing to preserve trapped air.

Transfer batter to the prepared dish and level the surface. Bake until the cake springs back lightly and a skewer comes out clean. Remove from the oven and allow it to cool completely before soaking.

Whisk coconut milk, condensed milk, and evaporated milk until smooth. Ensure the mixture is fully blended so the sweetness and fat distribute evenly during soaking.

Pierce the cooled cake evenly using a fork or skewer. Pour the milk mixture slowly, allowing it to seep in gradually. Refrigerate for at least 4 hours, preferably overnight, for full absorption.

Beat heavy cream with powdered sugar until soft, spreadable peaks form. Stop once the cream holds shape without stiffness, keeping the topping light.

Spread whipped cream evenly over the soaked cake. Sprinkle toasted desiccated coconut across the surface for texture and aroma.

Refrigerate the finished cake for an additional hour before slicing. Serve chilled to maintain clean layers and balanced flavour.