For breakfast, brunch, or dessert. Choose bananas that are ripe but not too soft and mushy for this recipe.
In advance: Toast almonds until golden and fragrant, about 3-4 minutes in a 350 °F oven or toaster oven, stirring at least once, and watching closely (careful not to burn them!) Set aside and let cool.
In a nonstick frying pan or skillet, add brown sugar and water, and stir. Warm over medium-low heat until sugar has absorbed water and starts to bubble, about 3-4 minutes.
Slice bananas, about ¼ inch thick, to get ready to add to the sauce with the toasted nuts.
Take the pan off the heat and add in vanilla, salt, cinnamon if using, and rum. Return pan to heat and reduce to low. Gently fold in bananas and nuts until coated with sauce.
Let cook another 2 minutes, then add butter.
Serve warm as a topping or filling for crêpes, over waffles, or over your favorite flavor of ice cream; vanilla or cinnamon ice cream would be nice, complementary flavors, but... peanut butter and chocolate ice cream? coffee ice cream? Go wild and pick something else, if you want.