For the Espresso Nightcap: Combine the milk, heavy cream, espresso, and amaretto liqueur, in a medium saucepan. Place over low heat, stirring constantly until hot but not boiling, about 3 to 5 minutes.
For the Vanilla Cream: In a large mixing bowl, beat the cream until thick Add the powdered sugar and vanilla. Continue to beat until cream holds soft peaks.
To serve: Pour the Espresso Nightcap into 4 (8-ounce) mugs. Dollop with the Vanilla Whipped Cream and serve immediately.