Preheat the oven to 350°F (175°C). Grease an 8-inch cake pan with coconut oil.
In a large mixing bowl, whisk together the all-purpose flour, almond flour, coconut sugar, baking powder, baking soda, and salt.
In a separate bowl, whisk together the melted coconut oil, almond milk, apple cider vinegar, and vanilla extract.
Add the wet ingredients to the dry ingredients and stir until well combined.
Fold in the blackcurrants and chopped mango.
Pour the batter into the prepared cake pan and bake for 30-35 minutes or until a toothpick inserted into the center of the cake comes out clean.
While the cake is baking, prepare the icing by whisking together the powdered sugar, vegan butter, almond milk, and vanilla extract in a mixing bowl until smooth and creamy.
Once the cake has finished baking, remove it from the oven and let it cool in the pan for 10-15 minutes. Then, transfer it to a wire rack to cool completely.
Once the cake has cooled, spread the icing on top using a spatula or knife.
Serve and enjoy your vegan blackcurrant and mango cake!