In a medium saucepan, combine the milk, coconut milk, and sweetened condensed milk, beating well to combine.
Bring the mixture to a simmer over medium-low heat, stirring occasionally so the mixture doesn't burn to the bottom of the pan. Once it comes to a simmer, add the bar finger until the mixture is smooth.
Remove the pan from the heat and add the vanilla. Serve the hot chocolate and decorate with whipped cream and grated coconut.