Preheat the oven to 350°F (175°C). In a large mixing bowl, mash the ripe bananas until smooth. In another bowl, cream together the butter and sugar until light and fluffy. Add the eggs one at a time, mixing well after each addition. Stir in the mashed bananas and vanilla extract.

Combine Dry Ingredients

In a separate bowl, whisk together the flour, baking soda, baking powder, cinnamon, and salt. Gradually add the dry ingredients to the banana mixture, stirring until just combined.

Bake the Cake

Pour the batter into a greased 9x5 inch loaf pan and smooth the top. Bake in the preheated oven for 60-70 minutes or until a toothpick inserted in the center comes out clean. Allow to cool in the pan for 10 minutes before transferring to a wire rack.

Banana Rum Glaze

Make the Glaze

In a small bowl, whisk together the powdered sugar, dark rum, and banana puree until smooth. Drizzle over the cooled cake.

Candied Walnuts

Prepare the Walnuts

In a saucepan over medium heat, combine the sugar, water, and cinnamon. Stir until the sugar has dissolved. Add the walnuts and cook, stirring frequently, until the walnuts are golden and caramelized. Spread on a parchment-lined baking sheet to cool.

Assembly

Serve

Top the spiced banana cake with candied walnuts and serve with a scoop of vanilla ice cream if desired.