Preheat oven to 350 degrees. Lightly coat a baking sheet with oil.
In a large bowl, whisk together the flour, salt, baking soda, cinnamon and allspice. Mix in the oats and cranberries.
In a medium bowl using a whisk blend the oil, sugar and vanilla extract until the sugar is smooth.
Add the mashed banana and blend until the banana is completely pureed. Stir the mixture into the dry ingredients until well combined.
Drop the batter by tablespoonfuls onto the prepared baking sheet, 1 inch apart, to make 24 cookies. Flatten the cookies slightly with the back of a wet spoon.
Bake the cookies for 15 to 18 minutes, until they are golden brown and almost firm to the touch.
Cool on the baking sheet on a wire rack for about 5 minutes, then remove the cookies from the baking sheet and continue to let them cool on a rack.
