Grease and flour a bundt cake pan and set it aside.
In a large bowl, whisk together the flour, sugar, baking soda, salt and cinnamon.
In a separate bowl, mix the eggs, oil, orange juice and vanilla extract.
Add the wet ingredients to the dry ones and whisk until incorporated.
Fold in the chopped apples, coconut and pecans.
Pour the batter into the prepared pan and bake in a pre heated oven at 165°C – 325°F for about 1 ½ hour or until a tester comes out clean.
Shortly before the cake is done, make the glaze. Melt the butter in a large saucepan, stir in the sugar, buttermilk, and baking soda, and bring to a good rolling boil, stirring constantly. Boil for 1 minute.
Pour the sauce over the hot cake in the pan as soon as you remove it from the oven, making sure that it runs down the sides and the middle to soak the cake uniformly.
Let the cake stand for 1 hour inside the pan, then turn it out onto a rack to cool completely.
This cake will stay fresh in the fridge for up to a week as the glaze helps it retain its moisture.