Preheat oven to 180 C and prepare the muffin tin with paper liners
In a large bowl whisk together oil, sugar and eggs. Stir in treacle, buttermilk and vanilla.
In another bowl whisk bran, flours baking powder baking soda and salt.
Add dry mixture to wet until just combined. Don't worry if its still a bit lumpy.
Spoon into prepared tins
Bake for 12-15 mins until top springs back when lightly touched.
Allow to cool slight before removing from the pan.
These will last in a tin on the counter for a week or freeze up to 3 months