Swirl peanut butter into ice cream. Place in freezer 30 minutes or until firm enough to spread.
Spread 1/4 cup ice cream mixture onto each of 8 gingersnaps. Top with remaining 8 gingersnaps. Place sandwiches on a 15- x 10-inch jelly-roll pan; freeze until firm. Wrap sandwiches in plastic wrap, and store in freezer.