Prepare the crust by mixing chocolate cookie crumbs with melted butter. Press into a pie pan and refrigerate until firm.
In a microwave-safe bowl, melt white chocolate chips in short bursts, stirring until smooth. Allow to cool slightly.
In a large bowl, beat softened cream cheese with powdered sugar until creamy. Fold in melted white chocolate and peppermint extract.
In another bowl, whip heavy cream to stiff peaks and gently fold into the cream cheese mixture until well combined.
Pour the mousse into the prepared crust and smooth the top. Refrigerate for at least three hours or until set.
Serve chilled, garnished with whipped cream and crushed peppermint candies if desired.
