Place the water, rolled oats, and vanilla in a small pot over high heat. Bring it to a boil and then reduce the heat to low, cover, and simmer for 10 minutes.
While the oats are cooking, make the bananas. Melt the coconut oil in a small frying pan over medium-high heat. Slice the bananas and sprinkle the brown sugar over both sides.
Add them to the pan in a single layer and fry until they're golden brown, about 1-2 minutes. Flip the bananas over and let them caramelize on the other side, about 1-2 minutes more.