Alternate layers of the softened vanilla ice cream and root beer in each popsicle mold, filling them almost to the top. Pour the root beer slowly, as it will foam.
Insert the popsicle sticks.
Freeze overnight, or until the popsicles are completely firm.
To remove, run the outside of the mold under warm water for a few seconds until the popsicles release easily.
Notes
Slightly softened ice cream is easier to layer into the molds.
Pour the root beer slowly to reduce foaming and prevent overflow.
If using disposable paper cups, peel away the cup before serving.