In a food processor, crush the Oreo cookies until they form fine crumbs.
In a mixing bowl, combine the Oreo crumbs, softened cream cheese, and mint extract. Use a spatula or your hands to mix until fully combined. The mixture should be thick and moldable.
Scoop out tablespoon-sized portions of the mixture and roll them into ball shapes. Place the truffles onto a baking sheet lined with parchment paper.
Once all truffles are formed, place them in the freezer for about 30 minutes to set.
While the truffles are chilling, melt the dark chocolate in a microwave-safe bowl, heating in 30-second intervals, stirring in between until smooth.
Remove the truffles from the freezer. Using a fork or dipping tool, dip each truffle into the melted chocolate, shaking off any excess.
Before the chocolate hardens, sprinkle the tops with crushed mint chocolate candies for an added minty crunch.
Allow the truffles to set on the baking sheet until the chocolate is hardened. For quicker setting, you can place them in the refrigerator for about 10-15 minutes.
If desired, sprinkle a pinch of sea salt over the top of each truffle for a sweet and salty combination.
Notes
For a sweeter touch, sprinkle sea salt on top before the chocolate hardens.