In a bowl, mash the ripe bananas until smooth, ensuring no large lumps remain.
In a medium saucepan, combine milk, sugar, cinnamon, salt, vanilla extract, and mashed bananas. Whisk well to blend flavors.
Heat over medium-high heat, stirring occasionally. Slowly whisk in the cornstarch until fully dissolved and smooth.
One at a time, whisk in the egg yolks, ensuring each is fully incorporated before adding the next. This will help prevent curdling.
Continue stirring until the mixture thickens and reaches a gentle boil (about 5 minutes). Reduce heat if needed to prevent burning.
Once large bubbles begin to pop, remove from heat and stir in the butter until fully melted and combined, giving it a glossy finish.
Let the pudding cool at room temperature before transferring to the refrigerator for 2-3 hours to set completely.
Serve chilled, topped with banana slices, whipped cream, and wafer cookies for added texture and flavor. Drizzle caramel on top for an extra treat.