Buttery Rum banana bread

I usually don't like butter in my banana bread recipe but this one is pretty good.

3 to 4 ripe bananas, smashed

1/3 cup melted butter

3/4 cup light brown sugar

1 egg, beaten

1 teaspoon vanilla

1 tablespoon rum (optional)

1 teaspoon baking soda

1/2 teaspoon salt

1 1/2 cups flour

Preheat the oven to 350°F. With a wooden spoon, mix butter into the mashed bananas in a large mixing bowl. Mix in the sugar, egg, vanilla and bourbon, then the spices. Sprinkle the baking soda and salt over the mixture and mix in. Add the flour last, mix. Pour mixture into a buttered 4×8 inch loaf pan. Bake for 50 minutes to one hour, or until a tester comes out clean. Cool on a rack. Remove from pan and slice to serve.