Preheat the oven to 350°F (175°C) and line a cupcake pan with cupcake liners.
In a mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.
Add in the eggs, one at a time, beating well after each addition.
Mix in the mango puree, milk, lime zest, and lime juice until fully combined.
In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.
Gradually add the dry ingredients to the wet mixture, mixing until just combined and evenly moist.
Evenly distribute the batter into the cupcake liners, filling them about two-thirds full.
Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
Once baked, allow the cupcakes to cool in the pan for 5 minutes, then transfer them to a cooling rack to cool completely.
While the cupcakes cool, prepare the cream cheese frosting. In a mixing bowl, beat together the softened cream cheese and butter until smooth and creamy.
Gradually mix in the powdered sugar, then add the key lime juice until well combined.
Once the cupcakes are fully cooled, frost them generously with the cream cheese frosting.
Garnish with lime zest on top of each cupcake for a refreshing touch.