Combine flour, sugar, baking powder and baking soda and salt in a large bowl.
Add coconut and mix to combine.
In a small bowl mix egg, coconut oil and mango pulp.
Add to the flour mixture and stir until just blended.
Now make the crumb topping. In a small bowl bowl combine flour, oats, coconut oil, sugar and coconut flakes. Rub the mixture with your hands to make large "oaty" clusters.
Pour batter into a 9" round and well-oiled pan and then sprinkle the crumb topping.
Bake at 350F/180C for 40-45 minutes, or until a toothpick inserted in the centre comes out clean.