Special equipment: 4 (8-ounce) ramekins
Line the ramekins with plastic wrap creating a shell and leaving long flaps to cover the ramekins later. In a food processer, pulse gingersnap cookies with melted butter until small crumbs form for the crust. Press half the cookie crumb mixture, dividing evenly, firmly into the bottom of each ramekin. Reserve the other half of the crumb mixture for the topping.
In a large bowl, whisk heavy cream with sugar until soft peaks form. In a separate large bowl, add the espresso powder and condensed milk and blend until espresso powder is dissolved. Whisk in Irish cream then fold in whipped cream. Pour evenly into the ramekins. Top with remaining gingersnap crumbs and cover with the extra plastic wrap, pressing to compact mixture. Freeze until set, about 5 hours. To serve, remove plastic wrap from top and then gently turn ramekins over to release dessert onto a serving plate. Gently remove plastic wrap.