Slow-cooked plantains achieve soft and sweet perfection without the need for a frying pan and oil. Preparing plantains in a slow cooker also requires less attention than a stovetop frying pan, and solves the problem of undercooking. Though banana-like in appearance, plantains must be cooked to be eaten, and should be soft and nearly black when prepared for the best results. The longer cook time with a slow cooker is worth the wait to enjoy the taste and benefits of a healthier version of plantains.
Cut the ends off the ripened plantains, and peel the plantains as you would peel a banana
Slice the plantains into large-size wedges, about 1/4 inch thick. Slice the plantains on the diagonal for longer slices or, if you prefer, slice the plantains into medallion-shaped pieces.
Brush a little melted salted butter on the plantain slices, and follow up with a light sprinkle of granulated or brown sugar. If you prefer not to use butter, spray plantain slices with cooking spray or oil instead. Skip the sugar and use a very light sprinkling of salt if you prefer to bring out the plantains' natural sweetness, or want a more savory dish.
Place a metal rack in the bottom of the slow cooker, and add just enough water to cover the bottom. This technique uses steam to help cook the plantains while raising the slices above the water to keep them dry enough to caramelize, especially when you use sugar.
Set the slow cooker temperature to low, and cook for 2 hours. Test for softness during cooking, and add more water if necessary to keep the bottom of the pot covered.
Remove the plantains from the slow cooker to a platter or bowl and serve while hot.