Directions

1. For the crust: In a small heavy bottom saucepan over low heat, melt the butter and chocolate. Remove from the heat. Finely crush the chocolate wafers in a plastic bag with a rolling pin, or use a food processor. In a large bowl, combine the wafer crumbs with the melted chocolate and blend until the crumbs are moistened. Reserve 1 1/4 cups crumb mixture in a small bowl. Press the remaining crumb mixture onto the sides and bottom of a 9-inch diameter springform pan with 2 3/4-inch high sides. Freeze for 1 hour. For the glaze: In a large heavy bottom saucepan, bring the cream and corn syrup to a boil. Remove from heat, add the chocolate, and whisk until it is melted and smooth. Let stand until cool but still pourable, about 1 hour. For the filling: In a large bowl, working quickly, mix the ice cream, crushed candies, and extract until blended. Spoon half of the ice cream into the crust, spreading it evenly. Put the remaining ice cream mixture in the bowl in the freezer. Sprinkle the reserved 1 1/4 cup cookie crumb mixture over the ice cream in the springform pan, press the crumbs down gently. Pour 1 1/4 cup of the chocolate glaze over the ice cream in the springform pan. Freeze for 1 hour. Top with the remaining ice cream, and spread evenly. Freeze until firm, about 4 hours. Stir the remaining glaze over low heat, just enough so that it is pourable but not warm. Pour the glaze over the ice cream, and spread evenly. Freeze overnight. Run a sharp warm knife between the pan sides and the crust to loosen the cake. Release the pan sides and transfer the cake to a platter. Garnish the cake with Candy Brittle.;
2. In a heavy bottom small saucepan over medium-low heat, cook the sugar, water, and corn syrup until the sugar dissolves. Increase the heat and boil, without stirring, until a candy thermometer registers 300 degrees F, about 15 minutes. Place a 24-inch long sheet of foil on your work surface. Be extremely careful, the syrup is extremely hot. Pour the boiling syrup in wide zigzag lines across the foil. Working quickly and using an oiled offset metal spatula, spread the syrup evenly onto the foil, leaving a 1-inch border. Immediately sprinkle with all the candies, pressing the larger pieces into the syrup to make sure they stick. Be careful not to touch the syrup. Cool completely. Break off irregular pieces of the brittle and peel off the foil as you go. Press the brittle upright, candy side out, onto the top and sides of cake and freeze.;