Grease heat-proof bowl with butter; set aside. In heavy-bottomed saucepan set over medium heat, stir together 2 tablespoons butter, coconut milk, sweetened condensed milk, chocolate, cocoa powder and vanilla; bring to simmer. Reduce heat to medium low; cook, stirring constantly, until chocolate is melted and mixture is smooth and thick, about 10 minutes.
Pour mixture into prepared bowl; cover with plastic wrap and refrigerate until cooled completely, about 3 hours or overnight.
Using greased tablespoon and with greased hands, roll tablespoonfuls of mixture into 1“ balls. Place on greased, parchment paper–lined baking sheet. Freeze for 15 minutes; roll each ball in chocolate sprinkles, pistachios and/or coconut (if using), as desired Place in mini-muffin paper cups. Refrigerate until serving
● Refrigerate prepared truffles in airtight container for up to 1 week or freeze for up to 1 month.
● Roll truffles in chopped nut, candy or cookie crumbs of choice.