Banana and blueberry muffins

1) Heat oven to 180C/fan 160C/gas 4 and line a 12-hole muffin tin with paper muffin cases.
2) Mix the flour, bicarbonate of soda, sugar and oats in a large bowl. Make a well in the centre.
3) In a separate bowl, mash the bananas, then add the buttermilk, oil and egg whites stirring until evenly combined.
4) Pour the banana mixture into the flour well and stir. The mix will look lumpy but don’t over-mix.
5) Add the blueberries and give it one more stir.
6) Divide the mix between the muffin cases. They will be quite full.
6) Bake for 18-20 mins until risen and dark golden. Cool for 5 mins in the tray before lifting out onto a rack to cool completely.