wisk together the flour, salt and baking powder and set aside. In the bowl of a mixer cream together the sugar and margarine, add the banana, agave, and vanilla and mix well. Slowly add the flour mixture and mix until it is well blended.
Wrap and chill at least 30 minutes before baking.

Preheat oven too 400 (f). Roll out on a floured board and cut out shapes. Place shapes on parchment lined (or lightly oiled) cookie sheet and bake for 8 minutes. Don't let the cookies brown.
Cool on racks and decorate