Peel the bananas and cut them into thin slices: the thickness depends on how you want your chips to be crispy, but keep in mind that the more thicker they are, the longer it takes to dry them. I 've cut them quite thin, about 2mm thick.

Arrange the slices on a baking sheet lined with parchment paper so that they don't overlap, sprinkle with plenty of lemon juice to taste and cinnamon.

Put the banana slices in the oven, preheated at 200°F; after half an hour turn the slices and put them back in the oven for another half hour.

After 1 hour cooking, turn off the oven and let the banana slices tightly closed until the oven has cooled down, so they will dry well in the center due to the heat remaining in the oven. Once the banana chips have cooled down, remove them gently the banana from parchment paper using a spatula.