Preheat your oven to 350°F (175°C). In a mixing bowl, combine the cake flour, baking powder, baking soda, salt, and granulated sugar. Gradually stir in milk, neutral oil, egg, and vanilla extract, mixing until smooth. Pour into a greased cake pan and bake for about 15 minutes. Cool completely before layering.

In a small bowl, sprinkle gelatine powder over cold water and let it bloom for 5-10 minutes. Prepare the mango puree while it blooms.

Blend ripe mango chunks until smooth to make the mango puree. Reserve some for the mango curd.

Dissolve bloomed gelatine in a saucepan over low heat and mix it with the mango puree until combined.

Whip the cream with powdered sugar until stiff peaks form, then fold in the mango-gelatine mixture gently.

Pour the mousse mixture over the cooled cake and refrigerate for at least 2 hours.

Heat reserved mango puree in a saucepan, add granulated sugar, and stir in a cornstarch slurry until thickened. Remove from heat and stir in butter.

Once the curd cools, pour it over the mousse layer and swirl for decoration. Refrigerate overnight before serving.