Add cream to a small saucepan. Bring to a simmer.
Add chocolate and allow to melt then whisk until smooth.
Add vanilla, cayenne and cinnamon, then simmer on low for 3 minutes, whisking occasionally.
Remove from heat and pour into ramekin.
Refrigerate for 4 hours until set.
To make this dish vegan:
Substitute the thickened cream for coconut cream. Most dark chocolate will be vegan-friendly already; check the label if you’re unsure.