In a small bowl put dry ingredients together (flour, salt and baking soda). Set aside.
In large bowl mix together mashed bananas and sugar. Add softened butter, vanilla and egg. Stir until combined, then sift in dry ingredients. Mix well.
Pour batter in to greased and floured bread pan. Bake at 350F for 50 minutes. Make sure it is cooked all the way through by checking with a toothpick before removing! Let cool 10 minutes before serving.