1. Pre heat the oven 200C /180 fan /Gas mark 6.
2. Line a muffin tray with muffin cases.
1. Mash the bananas with a fork and put to one side.
2. Next, in a large mixing bowl, cream together the sugar and butter, until the mix is fully combined and pale in colour.
3. Next slowly combine the eggs, one at a time whilst continually mixing.
4. Fold in the banana and blueberries.
5. Mix the flour, then spoon it into the prepared muffin cases.
6. Bake in the preheated oven for around 20 minutes, by which time the muffins should be dark, rounded and peeking out of their cases.
7. Allow to cool slightly in their tin before removing to a wire rack.
Remember -all cooking appliances vary in performance, these cooking instructions are guidelines only.