Preheat the oven to 180°C, gas mark 4 and line a baking tray with baking paper.
In a large bowl, mix the buckwheat, rolled oats, coconut flakes, pumpkin seeds, orange zest, salt and hazelnuts together.
In a small saucepan, over medium-low heat, add the coconut oil, maple syrup, orange juice and vanilla extract. Stir until the oil is melted. Pour over the dry ingredients. Stir well.
Spread the granola evenly across the baking tray. Bake in the oven for 15 minutes before rotating the tray around and bake again for 5-6 minutes. It should be golden brown in appearance.
Remove the tray from the oven and leave to cool completely.
Once the granola has cooled, sprinkle the sultanas and cocoa nibs over it. Carefully break the slab into smaller chunks using your hands. Serve with slices of orange and enjoy.