Melt the butter in a large skillet over medium heat.

Add the brown sugar, cinnamon and lemon zest, then stir to dissolve the sugar (about 1 minute). NOTE: If the heat is too high, the butter and sugar will separate instead of combining to form a sauce.

Add the bananas and spoon sauce over each piece. Cook until the bananas are glossy and golden on the bottom (about 1-2 minutes), then flip the bananas and continue cooking until very soft but not falling apart (about 1-2 minutes).

Remove the skillet from the heat and turn off the burner.

Add the rum and wait until the rum has warmed slightly, about 5 seconds. Wave a lit match over the pan until the rum ignites, shaking the pan to distribute the flame evenly.

When the flames die out, divide the bananas and sauce among the four bowls of ice cream to serve.