1. Preheat oven to 350° Fahrenheit and grease a baking sheet.
2. Place the butter in a large mixing bowl.
3. In a small bowl, combine the cassava flour, baking soda, and salt; mix well.
4. Cut the cassava flour mixture into the butter until the mixture looks like very course crumbs.
5. In another bowl, whisk together the eggs and coconut sugar.
6. Pour the egg mixture into the butter and cassava flour mixture. Add the coconut flour; mix well.
7. Fold in mangoes and coconut.
8. Form dough into a 1" thick round on the prepared baking sheet.
9. Cut into 8 wedges; do not separate the wedges.
10. Bake for 15-20 minutes.
11. Cool and enjoy.