Pre-heat the oven to 175°C.
Beat the butter in a food processor until soft and creamy and gradually add the sugar. Add the eggs one by one. Add the flour, baking powder and salt and mix on the highest setting for about another 2 minutes.
Peel and cut the mango into wedges.
Grease the loaf tin with a little butter and pour in half the batter. Arrange half the mango wedges on the batter and spread the rest of the batter over the top. Arrange the remaining mango wedges over the cake and bake in the middle of the oven for about 60 minutes.
Check the doneness with a skewer. Stick it in the middle and if it comes out dry, the cake is ready. If not, bake an extra 10 minutes and check again.