Preheat oven to 350°F (175°C) and prepare a 9” springform pan by greasing it lightly. Whisk together cake flour, baking powder, baking soda, and salt in a mixing bowl. Combine wet ingredients - granulated sugar, milk, neutral oil, and vanilla extract until smooth. Pour into pan and bake for about 15 minutes. Allow to cool completely.

Bloom gelatin in cold water for 5 minutes, then dissolve over low heat. Puree most mango chunks in a blender, then mix in dissolved gelatin. Whip cream and powdered sugar until stiff peaks form; fold in mango puree. Pour mousse over the cooled cake and chill.

Heat remaining mango puree with sugar until warm. Create a cornstarch slurry with cold water and stir into warmed mango mixture; cook until thickened for 2-3 minutes. Remove from heat, stir in butter, and strain curd. Cool slightly before spreading on mousse layer.

Cover the cake with plastic wrap and refrigerate for at least 12 hours, preferably overnight to enhance flavors and texture. This allows layers to set beautifully.

Remove cake from springform pan when serving. Slice with a warm knife and plate with extra mango slices and mint leaves.