Heat sugar, salt, and water together in a small saucepan over medium heat without stirring, until sugar is completely dissolved.
Stir in butter and cannabis butter until melted and mixture is smooth.
Stir in cocoa powder until mixture is smooth.
Remove from heat, stir in vanilla and liqueur, if using.
Transfer mixture to a small jar, let cool until warm to the touch, and start painting you artist of love you!