Berry Ice Cream Pie

Preheat the oven to 350°. In a bowl, stir the cracker crumbs, brown sugar and butter until evenly moistened. Press the crumbs into a 9-inch glass pie plate and bake for 10 minutes, until lightly browned. Let cool completely. Meanwhile, line another 9-inch pie plate with plastic wrap and spread with 1 pint of the ice cream. Top with plastic wrap and freeze until firm, about 10 minutes. Spread another pint of ice cream on top of the plastic, cover with plastic wrap and freeze. Repeat with a final layer of ice cream and freeze until firm. Meanwhile, in a saucepan, boil the vinegar over moderate heat until reduced to 1/3 cup, about 15 minutes. Add the 2 pints of blueberries and bring to a boil. Simmer over moderately low heat, crushing the berries, until thick and jammy, 8 to 10 minutes. Transfer the mixture to a bowl and freeze until chilled. Transfer the top layer of flattened ice cream to the crust, spreading it to the edges. Top with half of the blueberry mixture. Repeat with the middle layer of ice cream and the remaining blueberry mixture and top with the final layer of ice cream. Freeze until firm, about 30 minutes. Cut the pie into wedges and serve with fresh blueberries.