Preheat oven to 180 degrees celsius. Line muffin tin with 10 cupcake papers.
In a large mixing bowl sieve together buckwheat flour, coconut flour, tapioca flour, baking powder and cardamom powder.
Add rapadura sugar to the mixing bowl and use a whisk to combine.
In a seperate medium sized mixing bowl whisk together orange juice, zest and olive oil.
Pour wet ingredients into dry ingredients and whisk until just combined.
Spoon batter into cupcake papers. Place into oven and bake for 30 minutes, or until golden brown on top and skewer comes out clean when inserted into the middle of a muffin.
Once baked, remove from oven and allow to cool in tin slightly before transferring to cooling rack.