Preheat the oven to 325°F. Grease and flour a standard Bundt pan.
Whisk together flour, baking soda, and 1 teaspoon of the cinnamon. In the bowl of an electric mixer fitted with a paddle, beat the sugar, eggs, oil, vanilla and orange juice until combined.
With the mixer on low, add dry ingredients just until incorporated. Fold in the apples, walnuts or pecans, and coconut, then spoon the batter into the prepared pan and smooth the top with a spatula. Bake for 1 hour and 15–20 minutes, or until a toothpick inserted in the center comes out clean.
Cool in pan for 15 minutes, then invert onto a wire rack set over baking sheet. Puncture the top all over with a skewer to create deep holes for the glaze to soak into.
For the glaze, combine the sugar, butter, baking soda, and buttermilk in a medium sauce pan. Cook over medium heat, stirring constantly, until the mixture comes to a boil, about 5–8 minutes. It should be foamy and begin to turn a light brown. Pour the hot glaze over the warm cake. There will be more glaze than needed. Save the remainder to pour over individual slices.
Place the cake on a cake plate, let cake rest 1 hour before serving, and serve warm.