Gather ingredients: cocoa powder, cocoa butter (or coconut oil), sugar (or sweetener), pinch of salt, vanilla (optional)
Prepare a double boiler: simmer water in a pot, set a heatproof bowl on top without touching the water
Melt cocoa butter until fully liquid
Stir in cocoa powder gradually until smooth
Add sugar (and salt) and stir until dissolved and glossy
Add vanilla if using
Remove from heat and let cool slightly
Pour into molds
Refrigerate until set (or cool at room temperature if the recipe is oil-based and will set)
Unmold and store in a cool, dry place, wrapped or in an airtight container