In the 4 quart pot, mix the first can of evaporated milk, cocoa, and chocolate chips
1 oz unsweetened cocoa powder, 2 oz semi-sweet chocolate chips, 12 fl oz evaporated milk
Heat on medium and stir until chocolate chips melt together with cocoa and milk. Stir constantly.
Add the remaining can of evaporated milk
12 fl oz more evaporated milk
Stir until combined well
Add the remaining ingredients, except alcohol: the 2 cans of unsweetened coconut milk, the can of cream coconut, the can of condensed milk, cinnamon, and vanilla extract
14 oz condensed milk, 15 fl oz cream of coconut, 27 fl oz unsweetened coconut milk, 1 tbsp cinnamon, 1 tbsp vanilla extract
Stir until all combined well, especially the cream of coconut
Let it cool for about 30 minutes, until it's not warm anymore
Add in the alcohol
4 fl oz creme de cocoa, 1 qt coconut rum
Use the immersion blender to blend the whole thing really well for a minute or two until it's all smooth.If using a standard blender, mix it in batches, for about 1 minute per batch. Pour the mix into the gallon pitcher
Stir all together well
Refrigerate for at 1 least an hour, but overnight is better
Stir each time before serving, as ingredients settle
Serve over ice, in a rocks glass