Preheat the oven to 325 degrees F. Line two large muffins tins with paper muffin liners. Mix the flour, baking powder, and salt in a small bowl.
In the bowl of the electric mixer, cream the softened butter and sugar. Beat until light and fluffy, about 3-5 minutes. Scrape the bowl, then turn the mixer on low and add the eggs, vanilla and flour mixture. Scrape the bowl again and add the crushed pineapple, diced mango, and 3/4 cup shredded coconut. Mix until smooth.
Divide the batter evenly between 24 muffins liners. Then sprinkle the remaining shredded coconut over the muffin batter. Place the muffin tins in the oven and bake for approximately 25 minutes. Insert a toothpick in the center of a muffin. If it comes out clean, remove the muffins from the oven. Cool for at least 5 minutes in the muffin tins, then flip the muffins out of the pans.