Preheat the oven to 350 degrees F. Line a 12 cup muffin tin with cupcake liners or grease with cooking spray.
Lay a clean kitchen towel on the counter and spread the zucchini out on the towel, cover with another clean towel and let sit 10 minutes.
Meanwhile, combine the buckwheat flour, coconut flour, cacao or cocoa powder, baking soda and salt in a large mixing bowl. In a small bowl wisk together the honey, coconut oil, vanilla, eggs and buttermilk. Stir in the shredded zucchini. Add the wet to the dry and mix until just combined. It is ok if there are still some clumps. Stir in the the chopped chocolate.
Divide the batter among the prepared muffin cups. In the same small bowl, stir together the buckwheat groats, maple syrup, coconut oil and a small pinch of salt. Sprinkle the mix overtop of the muffins.
Place in the oven and bake for 20-25 minutes or until a toothpick inserted into the center comes out clean. When the muffins come out of the oven, I like to sprinkle them with a little chopped chocolate and serve them warm.
*if you prefer, you can soak your buckwheat groats overnight to get more nutrients out of them and make digesting the buckwheat easier, but I honestly never do this because I just forget.