Melt the chocolate in a medium heat-proof bowl (like Pyrex) over a pot of simmering water (or use a double boiler).

Meanwhile, bring the coconut milk to a boil in a small saucepan with a lid. Turn off the heat and add the vanilla, cinnamon, cayenne, salt and yerba mate, cover and let steep for 5 minutes.

Strain the coconut milk mixture directly into the melted chocolate using a fine mesh sieve. Discard the tea leaves and whisk the chocolate and coconut milk until everything is smooth, melted and combined.

Pour the truffle mixture into a small, cover with plastic wrap and refrigerate for 2 hours or up to overnight.

Once the mixture has firmed up in the refrigerator, sift the cacao powder into a bowl. Use a 1 teaspoon measuring spoon, very small ice cream scooper or melon baller and scoop up the truffle mixture and roll it into a ball with your hands. Don't overwork the mixture or it will melt in your hands. Drop the ball into the cacao powder and roll around to coat. Repeat with the rest of the mixture.

Store in an airtight container in the refrigerator for up to 2 weeks.