Prepare the Caramel: In a large skillet, melt the butter over medium heat. Add the brown sugar and cinnamon. Stir until the sugar is dissolved and the mixture starts to bubble.

Add the Bananas: Add the banana slices to the skillet. Cook for about 2-3 minutes on each side, or until the bananas are tender and coated in caramel.

Finish: Add the lemon juice and vanilla (if using) to the skillet, and gently mix to coat the bananas well.

Serve: Serve the caramelized bananas warm, accompanied by ice cream or yogurt if desired.