Preheat oven to 350 degrees F.
Combine cake mix and 1/2 cup cold water. Beat 2 minutes. Beat in eggs, water, vanilla and oil. Mix well. Place ice cream cones in muffin tins or on cookie sheet and fill each 1/2 full with batter. Bake 20 minutes or until cake springs back to the touch. Frost and decorate when cooled, if desired.