In a small saucepan over medium heat, bring the cream to a simmer. This won't take long so watch carefully.
Once simmering, remove from heat and add the white chocolate chips. Let sit for a few minutes to melt and then whisk to combine. Let cool to lukewarm.
In a large bowl, beat the cream cheese with the butter until combined. Beat in the powdered sweetener, then beat in the white chocolate mixture until well combined.
Add mint extract and green food coloring to taste, then stir in the chocolate chips. Refrigerate 30 to 60 minutes to firm up.
Line a baking sheet with parchment paper. Use a 1 tablespoon cookie scoop and scoop the mixture onto the tray. Alternatively, you can roll tablespoons of the mixture into balls between wet hands. You will need to re-wet your hands frequently.
Freeze until very firm, at least 2 hours.
Chocolate Coating
In a heatproof bowl set over a pan of barely simmering water, combine the dark chocolate chips and the cocoa butter. Stir until melted.
Transfer the truffles to a plate and keep them in the freezer (they soften easily). Working with one at a time, dip each frozen truffle into the chocolate, tossing to coat with a fork. Lift out and tap the fork on the side of the bowl a few times to remove the excess chocolate.
Place on the parchment lined tray to set. Repeat with remaining truffles. The chocolate should set quickly if your truffles were frozen but if not, pop it in the fridge for 10 to 20 minutes.
Set another heatproof bowl over the pan of water and bring back to a light simmer. Add the white chocolate chips and stir until melted.
Transfer the melted white chocolate to a snack-size ziploc baggie with the tiniest tip cut off one corner. Drizzle over the truffles and let set.