Preheat the Oven to 175°C/340°F/Gas Mark 4.
Prepare baking tin with greaseproof paper. I like to leave some overhang to make it easier to lift the loaf from the tin once it is cooled.
Mix the flour, sugar, and salt in a bowl then set aside.
In a separate bowl mash the banana with a fork.
Melt the butter in a pan or microwave.
In a separate bowl mix together melted butter, eggs, and vanilla.
Add the mashed banana to the butter and egg mixture.
Add together the wet and dry mixture and stir until fully combined.
Coat the blueberries with flour.
Add the fresh blueberries to the mixture keeping a small handful aside and mix until evenly combined.
Transfer the batter into the loaf tin and spread evenly.
Place the extra blueberries at random on top of the batter.
Place the tin in the oven for approximately 55-60 minutes. Do not open the oven during baking time.
After 55-60 minutes check your loaf with a skewer and when it comes out almost clean it is ready to come out of the oven and be moved to a cooling rack.
Leave in the tin to fully cool as the bread will be too delicate to slice while it is still warm.