Preheat the oven to 180C Fan/200°C/gas mark 6/400°F and line a 12-hole muffin tin with muffin cases.
Puree, or mash the banana in a small bowl and set it to one side.
Pour the oil into a jug and beat in the eggs.
Put the flour, sugar, bicarbonate of soda and baking powder into a large bowl and mix in the oil mixture, followed by the pureed bananas and the vanilla extract.
Take the Valrhona Dulcey Feves and pecans and chop them lightly, you still want some quite large pieces.
Fold these into the mixture, then place equal quantities in the prepared muffin cases.
Place the muffins in the oven to cook for 25-30 minutes.
When the muffins are cooked, leave them in the tins to cool, when cool these muffins freeze really well, you can just give them 30 seconds in the microwave and they are defrosted, soft and gooey.