Begin by greasing a 9-inch pie plate with butter to prevent sticking.

In a food processor, pulse Oreo cookies until finely crushed.

Add melted butter and blend until fully combined, then transfer mixture into the greased pie plate.

Place crust in the freezer for 20 minutes to firm up.

In a medium saucepan, combine mini marshmallows and heavy whipping cream, stirring continuously over medium heat until melted.

Remove from heat, let cool, then stir in peppermint extract and red gel food coloring.

Fold half of the Cool Whip into the melted marshmallow mixture.

Spoon the creamy peppermint filling into the chilled Oreo crust, smoothing the top.

Cover the pie with plastic wrap and refrigerate for at least 6 hours, preferably overnight.

Just before serving, sprinkle crushed candy cane pieces over the top.