Preheat oven to 325F.
To a mixing bowl, add the buckwheat groats, oats, nuts, coconut, diced apples, chia seeds, coconut sugar, sea salt, and cinnamon. Stir to combine.
In a small saucepan over medium-low heat, warm the oil and maple syrup until melted and combined.
Spread the mixture evenly onto a baking sheet (or more baking sheets if making a larger batch) and bake for 25-30 minutes (or until fragrant and deep golden brown), stirring a bit near the halfway point to ensure even baking.
Wait until it has cooled completely. Place cooled granola in a sealed container that has an air-tight seal, and it should keep for a few weeks. Or store in the freezer up to 1 month or longer.