Pop popcorn in an air popper according to manufacturer's directions; transfer to a bowl and remove any unpopped kernels.
Place a sheet of aluminum foil on a work surface and spray with cooking spray.
Melt butter in a saucepan over medium-high heat.
Add marshmallows to melted butter and stir constantly until mixture is smooth; remove from heat. Quickly stir candy canes and peppermint extract into butter mixture until well blended.
Pour mixture over popcorn and mix until evenly coated. Allow popcorn mixture to cool.
Spray your hands with cooking spray and form popcorn mixture into balls; arrange on the prepared aluminum foil. Wrap each ball with plastic wrap when completely cooled.
