Melt the dark chocolate in a double boiler or in the microwave at 30-second intervals.
Heat the non-dairy milk until lukewarm (in a saucepan or in the microwave). Add in the cashew butter and whisk until you obtain a thick cashew cream.
Add the cashew cream to the melted chocolate and stir to combine. Place in the fridge to set for 30 minutes.
Add the cocoa powder to a bowl.
Scoop about 1 tablespoon of batter with a spoon or an ice cream scoop. Drop the batter into the cocoa powder. Cover the ball with cocoa powder, then roll it in the palm of your hands to form a small truffle. Coat with more cocoa powder if desired. Repeat until there's no truffle batter left.
Transfer the truffles to an air-tight container and store them in the fridge for 2 to 3 weeks. Always take them out of the refrigerator 30 minutes in advance for that perfect melt-in-your-mouth texture