Heat butter, brown sugar, and cinnamon in a skillet over medium heat, whisking constantly until it is well combined.
Add the vanilla and whisk. Then add the bananas cut side down, shaking the pan occasionally as they cook, until they are lightly browned 30-60 seconds.
Turn the over and sprinkle with a little kosher salt and allow to brown for another 30-60 seconds.
Remove from heat. Drizzle the rum over the top. Using a lighter, carefully light the rum and allow the bananas to flame until the fire goes out.
Place a scoop of ice cream in the waffle cone bowl or a regular bowl, top with the bananas and sauce, and serve.