Crush the Mint Oreo cookies into fine crumbs.
Mix the crushed Oreos with softened cream cheese and peppermint extract.
Shape the mixture into small balls, about 1 inch in diameter.
Chill the truffle balls in the refrigerator for at least 30 minutes.
Melt the semi-sweet chocolate in a microwave or double boiler.
Dip each chilled truffle ball into the melted chocolate, coating thoroughly.
Allow the chocolate to set, then drizzle with melted white chocolate, if desired.
Store the truffles in an airtight container in the refrigerator.
