Heat 1/2 cup milk or water in a saucepan
Add 1/4 cup cocoa powder
Add 1/4 cup sugar
Add 2 tablespoons butter or coconut oil
Add a pinch of salt
Add 1/2 teaspoon vanilla extract
Whisk until smooth
Cook on low heat until thick and glossy
Pour into a lined mold or tray
Refrigerate until set
Cut into pieces and serve