Start by peeling the ripe plantains. Cut off both ends and slice the skin lengthwise, then carefully remove the peel. Cut the plantains into thick slices, about 1 inch each.
In a large frying pan, heat 2 tablespoons of vegetable oil over medium heat. Once the oil is hot, add the sliced plantains in batches, making sure not to overcrowd the pan. Fry for about 3-4 minutes on each side until they are golden brown and slightly softened. Remove them from the pan and place them on a paper towel to drain excess oil.
While the plantains are still warm, transfer them to a mixing bowl and sprinkle with 1 teaspoon of salt. Using a fork or a potato masher, mash them until they are smooth but still have some texture.
Grease a muffin tin with the remaining 2 tablespoons of vegetable oil. Take a portion of the mashed plantains and press them into the bottom and up the sides of each muffin cup, forming a small cup shape. Make sure the walls are thick enough to hold the filling.
Preheat your oven to 375°F (190°C). Place the muffin tin in the oven and bake for about 15-20 minutes, or until the plantain cups are firm and slightly crispy.
While the cups are baking, combine your chicken and tomato sauce filling in a bowl. Add hot sauce to taste and mix until well combined.
Once the plantain cups are done baking, remove them from the oven. Carefully fill each cup with the spicy chicken mixture, then top with shredded cheddar cheese.
Return the stuffed cups to the oven for an additional 10 minutes, or until the cheese is melted and bubbly.
After the final baking, remove the Mofonguitos Maduros from the oven. Drizzle with vegan avocado mayonnaise and sprinkle with chopped cilantro, if using. Serve hot and enjoy the delicious flavors!