Pour the milk into a small saucepan over medium heat. Add the chocolate powder, peanut butter, and vanilla. Whisk until well combined and cook until hot. Be careful not to let it boil or the milk could curdle.
Pour into mugs & top with whipped cream and sprinkles. Serve immediately. Enjoy.
Side Note: Some peanut butters still have tiny grains of peanuts in them, if yours does, make sure to pour the finished hot chocolate through a fine sieve to remove all the peanut butter grains before pouring into the serving mugs.