Preheat oven to 350°F (175°C) and grease an 8-inch round cake pan.
In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt.
In a separate bowl, combine mango puree, oil, almond milk, apple cider vinegar, and vanilla extract.
Gradually pour the wet ingredients into the dry ingredients and whisk until just combined.
Pour the batter into the prepared pan and smooth the top.
Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean.
Allow the cake to cool completely in the pan before transferring to a wire rack.
Prepare the frosting by beating vegan butter, powdered sugar, and 2 tablespoons of mango puree until fluffy.
Apply the frosting to the cooled cake and serve.