Prep Vegan Buttermilk: In a small bowl, combine 1 cup of dairy-free milk with 1 tablespoon of apple cider vinegar. Allow this mixture to sit for about 5-10 minutes until it thickens slightly.

Make Sponge Batter: In a large mixing bowl, whisk together 2 cups of self-raising flour, 1 cup of caster sugar, 1 teaspoon of baking powder, and 1 teaspoon of bicarbonate of soda until combined. Slowly incorporate ½ cup of sunflower oil, 1 teaspoon of vanilla extract, the prepared vegan buttermilk, and 1 cup of mango purée.

Bake: Preheat oven to 180°C (350°F). Grease and line three 8-inch cake pans. Distribute the batter among the pans and bake for 25-30 minutes.

Cool Layers: Allow cooled cake layers to rest in the pans for about 10 minutes, then transfer to wire racks.

Prepare Buttercream: In a medium bowl, beat ½ cup of dairy-free butter until smooth. Gradually add 2 cups of powdered sugar and ¼ cup of mango purée.

Assemble Cake: Place one cake layer on a serving plate, add buttercream and drizzle with mango purée. Repeat with the second layer and stack the third on top.

Decorate: Coat the entire cake with remaining buttercream, sprinkle with desiccated coconut, and optionally garnish with fresh mango slices.