For the beans:
Line a skillet with a thin layer of water and sauté onion and garlic over high heat until onion is translucent and most of the water has cooked off, about 2 minutes. Add chili powder, cumin, a light dash of paprika, and a very light dash of cinnamon, stirring to coat everything. Continue to cook for about a minute, until fragrant and most of the liquid has cooked off. Add beans (with juices) and stir to combine. Reduce heat to low and mash beans well with a fork or potato masher a few times. You still want some whole and half beans and not a refried consistency. It will look very soupy; don’t be alarmed. Crank the heat to high and bring to a boil. Once boiling, reduce heat to medium-high and cook for 10 minutes. If it’s popping, cover for a few minutes, until it cooks down and stops popping. Stir the beans every minute or so, taking care to scrape the bottom and lift the beans. After 10 minutes, the mixture should have significantly reduced. It may still be a little soupy, that is all right — it will thicken as it cools — but if it’s really soupy, cook longer. Set aside and prepare "plantains" (recipe below). Once bananas are ready, add hot sauce (or cayenne powder) and lime juice and zest to taste, squeezing some lime over the bananas as well. Plate, serving bananas next to beans, or on top. Side of rice if desired. Season with salt and pepper and serve.
For the "plantains":
Slice peeled bananas into 1-inch chunks, and then slice each chunk in half lengthwise (down the center of the banana). Heat a nonstick skillet over high heat. You’ll know it’s ready when a drop of water sizzles. Divide banana chunks in half, setting half aside. Place the slimy insides facing down on the skillet, one at a time, in a row. It is important to remember the order, because as soon as you finish putting the last piece down, it’s time to flip the first one. When they’ve all been flipped once, remove one by one and set aside. Clean out the skillet and reheat if necessary. Repeat with remaining banana pieces. Once "fried" to perfection, drizzle with lime juice.