Place all ingredients in high-powered blender, blending on low speed for about 1 minute, until plantain is puréed. (If your blender is less powerful: Purée just your wet ingredients. Small pieces of plantain will be speckled throughout if your blender isn't as powerful. Then pour purée into bowl, add dry ingredients, and mix all together well.)
Scoop 1-ounce portions onto lined dehydrator tray or greased cookie sheet (if using a low-temperature oven).
Dehydrate cookies at 130 degrees for about 10 hours, depending on the dehydrator, until bites are brownie-like in texture: soft and chewy. (If you want your brownies to be "raw", dehydrate at 115 degrees.)
Cool brownies, and refrigerate for storage.
*How to peel green plantains — Have plantains at room temperature.
Cut off both ends.
Cut in half length-wise.
Cut each half in half again, width-wise.
Insert thumb between flesh and peel and unwrap sticky peel.