✓ Heat the milk in a saucepan over medium heat until it begins to steam, about 150°F (65°C), and small bubbles form around the edges.

✓ Mix cocoa powder, sugar, and vanilla extract in a small bowl; add a splash of hot milk and whisk until a smooth paste forms (no lumps).

✓ Fold the cocoa‑sugar paste into the remaining hot milk, stirring until fully incorporated and the mixture turns a deep, glossy brown.

✓ Heat the brewed coffee in a separate pot until it reaches a gentle simmer, about 160°F (71°C); avoid boiling to preserve flavor.

✓ Combine the coffee and the chocolate‑milk mixture in a large mug, stirring clockwise until the surface is uniformly dark and fragrant (do not overmix – excessive agitation can cause a thin, watery texture).

✓ Top the coffee with a generous swirl of whipped cream; the cream should hold its shape but begin to melt within seconds, creating a silky veil.

✓ Scatter chocolate shavings or sprinkles over the whipped cream; the garnish should melt slightly on contact, releasing a glossy sheen.

✓ Serve immediately while the mug is warm and the whipped‑cream crown is still soft; garnish with a single heart‑shaped cocoa dust if desired.