Prep the chocolate. Finely chop the dark chocolate so it melts quickly and evenly. Place it in a heatproof bowl.
Warm the liquid. Heat the milk or coffee until steaming but not boiling.
Pour it over the chopped chocolate and let it sit for 1–2 minutes.
Stir to melt. Gently whisk the chocolate mixture until smooth and glossy. If a few pieces remain, microwave in 10-second bursts, stirring between each, until fully melted.
Sweeten and season. Whisk in the maple syrup (start with 3 tablespoons), vanilla, and a pinch of salt. Taste the chocolate base; it should be slightly sweeter than you want the final pudding to be.
Fold in the yogurt. Add the Greek yogurt in two additions, whisking gently until just combined and uniform.
Avoid overmixing to keep it light.
Adjust consistency. If it’s too thick, add a splash of milk. If you prefer it sweeter, whisk in another small drizzle of maple syrup.
Chill to set. Spoon into serving dishes and chill for at least 1–2 hours. The texture will thicken into a mousse-like pudding as it cools.
Garnish and serve. Top with berries, shaved chocolate, or nuts right before serving for extra texture and flavor.