In a microwave-safe bowl, heat the dark chocolate chips in 30-second intervals, stirring after each interval until completely melted and smooth. Allow to cool slightly.
In a large mixing bowl, combine the Greek yogurt and cocoa powder. Use a hand mixer or whisk vigorously until well blended and the mixture is smooth without lumps.
Add honey or maple syrup, vanilla extract, espresso powder (if using), and salt to the yogurt and cocoa mixture. Mix until everything is thoroughly combined and creamy.
Drizzle the slightly cooled melted chocolate into the yogurt mixture. Carefully fold the chocolate into the yogurt until fully incorporated, ensuring a rich, creamy mousse texture.
Spoon the mousse into serving dishes or individual cups. Cover with plastic wrap and refrigerate for at least 1-2 hours to allow it to set properly.
Once chilled, garnish each serving with fresh berries and a sprig of mint for a refreshing touch.
Notes
Serve in clear glass cups to show off the rich chocolate color, and add a drizzle of honey on top for extra sweetness and visual appeal.