Refrigerate the brownies for 30 minutes or longer. Unwrap the brownies and slice in half by carefully placing them on their sides and slowly pressing a knife through each one. Place about three heaping tablespoons of ice cream on the bottom slice. Smooth out the ice cream and place on the top half. Wrap each one with wax paper and tie with a piece of twine. Place in the freezer to harden. Makes 12 servings.