Drain pears, reserving liquid for other uses. Cut pears into 1/4 inch pieces. Spoon ice cream into medium bowl. Let soften at room temperature for about 15 minutes; stir in diced pears. Return mixture to freezer; freeze until firm, about 2 to 3 hours. To make sandwiches, place a scoop of ice cream on half of the cookies. Top with remaining cookies; flatten slightly. Decorate by rolling edges in nonpareils. Serve immediately or wrap in plastic wrap and freeze until ready to serve.