In a large skillet, melt butter over medium-low heat until it begins to foam slightly.

Gently stir in dark brown sugar and cinnamon until a smooth, caramel-like sauce forms.

Cut each banana lengthwise, then crosswise into quarters (or slice into 1/4-inch rounds). Add the pieces to the skillet, ensuring they're coated in the buttery sauce.

Cook the bananas, stirring lightly, until softened but still holding their shape, about 3-5 minutes.

Add creme de cacao, stirring gently to incorporate, and heat the mixture through.

In a separate saucepan, warm dark rum over low heat until vapors form (do not boil). Carefully ignite the rum with a match or lighter.

Pour the flaming rum over the bananas in the skillet, tilting the pan slightly to spread the flames evenly until extinguished. Remove from heat.

Serve immediately over scoops of vanilla ice cream, garnishing with toasted pecans if desired.