1. Preheat oven to 300F.
2. Line a 13x18 inch half sheet rimmed baking sheet with parchment paper (a small difference in size won’t make a big difference in your crackers).
3. Make sure your parchment goes right up to each edge of the pan.
4. Peel plantains and set them out to room temperature (to make them easier to blend).
5. Place all ingredients in a blender or food processor (the food processor makes a HUGE difference and is really the way to go).
6. Blend until a completely smooth puree is formed, about 2-4 minutes (make sure you get between1/4 - 2 cups pureed plantain per batch).
7. Pour batter (it should look very much like hummus) onto the prepared baking sheet.
8. Use a rubber spatula to smooth it out and cover the entire sheet uniformly (this might take a couple of minutes, but it doesn’t need to be perfect). The batter should be about 1/8 inch thick.
9. Bake for 10 minutes. Remove from the oven and score the cracker batter with a pastry wheel, pizza cutter, or pastry scraper.
10. Make whatever size cracker you like from 1 ½ inch squares to extra large. The crackers will pull away from each other slightly while cooking and shrink up a bit, but not much.
11. Place back in the oven and bake for 50-80 minutes, until golden brown. The cooking time varies quite a bit with both exactly how much volume of plantain you have in the recipe and how green the plantains are. Greener ones take longer to cook (and typically taste better too) as do batches made with slightly larger plantains.
12. Keep an eye on them and don’t pull them out of the oven until they are a nice medium shade of brown (you can always taste one to see if it’s crisp enough, until you get the hang of this recipe).
13. Remove from oven and let cool slightly on the pan. Move to a cooling rack (you will probably be moving fairly big pieces of several crackers stuck together).
14. Once completely cool, you can break apart any crackers that are stuck together.
15. Store in an airtight container at room temperature.