In the meantime, gently cut brownies in half with a serrated knife.
Line a 1/2 cup measuring cup with plastic wrap and pack with softened ice cream. Fold the plastic wrap over the bottom tightly and remove from measuring cup. Loosely form with hands into a disc. Place in freezer. Repeat until you have four. Freeze for 15 minutes or until slightly hardened.
Unwrap ice cream and place on top of brownies. Top with the other half and gently squeeze the two together to make a snug sandwich. Eat immediately or re-wrap with plastic wrap and store in a freezer safe bag or container for up to a week or so. Best when eaten fresh.