In a large saucepan, combine marshmallows, sugar and two cups of rice milk. Stirring constantly, bring marshmallow mixture to a slow boil until sugar and marshmallows have dissolved. Remove from heat and allow to cool completely. Meanwhile combine gelatin, two cups of rice milk, and oil.  Allow to stand for five minutes. Using a mixer, beat gelatin, oil and rice milk mixture until foamy. Add vanilla. Combine all ingredients together and transfer to the frozen canister of an ice cream maker. Process according to manufacturer’s instructions (mine takes about 30 minutes).