In a large frying pan, melt the coconut oil (or alternative frying oil) and bring it to about 180°C (356 °F).
Mix all the dry ingredients in a large bowl.
In a small bowl, mix the wet ingredients. Start adding the melted butter to the buttermilk (or alternative). Make sure the melted butter has cooled off before adding it in. Mix well.
Add the eggs to the buttermilk and butter mixture. Mix well.
Pour the wet ingredients into the bowl with the dry ingredients.
Add the orange zest as well.
Mix everything together until well incorporated. Don't overmix as it will develop the gluten, resulting in a dense dough.
The donut batter should be thick and gooey, but not dry.
When your frying oil is ready, use a spoon to drop the batter into the hot oil. Don't take more than a tablespoon of batter. The smaller the donuts, the better.
Fry them until golden brown on all sides. This should only take a few minutes.
Take them out of the frying oil with a slotted spoon and lay them in a single layer on a large plate lined with kitchen paper. This should help absorb the excess oil and avoid leaving the donuts soggy and oily.
The donuts should be crispy on the outside and soft on the inside.
Powder them with some caster sugar.
Eat them while warm.
Serve and enjoy!