Whisk or mix together the milk, sugar, espresso powder, and cocoa until the sugar has dissolved. Stir in the heavy cream and vanilla., Freeze in an ice cream maker according to the manufacturer's directions., Stir the cookie bits into the soft ice cream and serve immediately. Or freeze for longer storage; see "tips," below., Don't have an ice cream maker? Simply pour the chilled mocha cream into a bowl, place the bowl in the freezer, uncovered, and stir the cream every hour. After about 4 hours or so, it'll be soft-serve consistency. Continue to stir and freeze until it's the consistency you like. While it won't be as creamy as churned ice cream, it'll be absolutely delicious.