Place a hearty scoop of ice cream in the center of each cookie and top with the remaining cookies, flat side down. Press down lightly to help the ice cream spread evenly to the edges.
Transfer the baking sheet with the cookie sandwiches to the freezer and freeze for 15-30 minutes.
Remove the ice cream sandwiches from the freezer and press sprinkles, chocolate chips or chopped nuts onto the ice cream to garnish, if desired.
Return the ice cream sandwiches to the freezer for 30 minutes or until ready to serve.
Notes
Ice cream sandwiches can be made up to 30 days in advance and stored in an airtight container in the freezer.