In a large mixing bowl, add mashed bananas and stir in melted butter. Mix in the sugar, egg, vanilla, and 1 tablespoon of raisin-infused rum. Add the cinnamon, nutmeg, and allspice. Stir to combine.
1 1/2 cup mashed overripe bananas, 1/3 cup salted butter, 3/4 cup raw or turbinado sugar, 1 large egg, 1 teaspoon vanilla extract, 1 tablespoon raisin-infused dark rum, 1 teaspoon cinnamon, 1/4 teaspoon nutmeg, 1/8 teaspoon allspice