Preheat oven to 325 degrees.
Grease a bundt pan very well. First use spray, butter or oil all over inside of pan. Then sprinkle tapioca starch all over inside of pan.
In a small saucepan add the sugar, cocoa powder, water and maple syrup and bring to a boil stirring occasionally. Once boiled remove from heat and add the baking soda and stir well.
In a medium bowl add the sugar and butter and beat well.
Add the eggs and oil and beat on medium speed until combined well and smooth.
In a small bowl add the dry ingredients and whisk.
Add dry ingredients to wet and mix on low speed.
Add the buttermilk and vanilla and beat on medium speed until batter is very smooth.
Fold in the coconut.
In a small bowl add 1 cup of plain batter to the cocoa mixture and stir well.
Spoon 1/2 of the plain batter into the bundt pan.
Top with the cocoa batter.
Top with the rest of the plain batter and use a knife to swirl batter together. Do not over mix.
Bake in oven for 60-70 minutes.
Remove from oven and allow to cool completely before removing cake from bundt pan.
Once cool you can top with the chocolate coconut sauce.