Put cookies in the freezer for 3-4 hrs. to harden. Allow ice cream to soften at room temperature for 3-5 min. Scoop ½ of ice cream over the bottom of a cookie; sandwich another cookie on top, bottom side against the ice cream between. Press cookies together to distribute ice cream; smooth edges with the back of a spoon. Repeat with remaining cookies and ice cream. Roll edges of ice cream sandwich in candy sprinkles or sprinkle candy on exposed ice cream), if desired. Wrap sandwiches in waxed paper; freeze 4 hrs. or until solid. Let stand at room temperature for 5-10 min. before serving.
DIPPED COOKIE VARIATION: Start this recipe by adding approx. 4 oz. dark chocolate melting discs (roughly ½ cup) to a microwave-safe dish. Microwave chocolate in 30 sec. increments, stirring between heatings, until mixture is smooth. Dip half of each cookie in melted chocolate to coat (or use a rubber spatula to lightly and evenly coat half of each cookie with chocolate, including top, bottom and edges). Place dipped cookies on wax paper; set aside at room temperature until chocolate hardens (2-3 hrs.). Transfer to freezer and follow recipe above.