Preheat oven to 350°F.

With a wooden spoon mix butter into smashed bananas in a large mixing bowl

Mix in sugar, egg, poppyseeds and vanilla

Sprinkle the baking soda and salt over the mixture and mix in

Add the flour last

Pour mixture into a buttered 4x8 inch loaf pan

Bake for 1 hour

Cool on a rack, remove from the pan and slice to serve