In a small pot, add your cocoa powder, sugar, and water
Heat over medium heat, whisking until the mixture is simmering and thoroughly combined
Add your milk, peanut butter, salt, coffee, and vanilla
Whisk until everything is completely combined (it might need to heat up a bit before the peanut butter totally mixes in)
You may want to run a spoon or rubber spatula along the inner edge of the pan in case any of the cocoa/sugar mixture is stuck in there where your whisk can’t reach
Heat until hot and almost simmering, but don’t let the milk simmer too hard or boil! It will scorch and mess up the flavor