PreparationMake chocolate sauce: Heat 2/3 cup whipping cream and 2 tablespoons butter in heavy medium saucepan over medium heat until butter melts. Remove from heat. Add chocolate; let stand 1 minute. Whisk until chocolate melts and sauce is smooth. Mix in vanilla extract. Cool sauce to room temperature, stirring occasionally, about 30 minutes. Make ice cream cake: Line bottom of 9 x 5 x 2 1/2-inch metal loaf pan with parchment paper, leaving overhang on long sides. Using back of spoon, spread 1 pint ice cream over bottom of prepared pan. Sprinkle evenly with 1 cup cookie crumbs. Spread another 1 pint ice cream over cookie crumbs. Freeze until ice cream is firm, about 20 minutes. Spread with 3/4 cup sauce; freeze 20 minutes. Spread with remaining 1 pint ice cream; sprinkle with 1 cup cookie crumbs, pressing crumbs into ice cream to adhere. Cover pan and freeze ice cream cake until very firm, at least 4 hours. (Can be prepared 5 days ahead. Keep cake frozen. Cover and refrigerate remaining sauce. Store remaining 1 cup crumbs airtight at room temperature.) Stir remaining sauce in heavy medium saucepan over low heat until warmed through; pour into small pitcher or bowl. Cut around pan sides to loosen cake. Turn cake out onto platter. Peel off parchment. Sprinkle top of cake with remaining 1 cup crumbs. Cut cake crosswise into slices. Serve immediately with warm sauce.
PreparationMake chocolate sauce: Heat 2/3 cup whipping cream and 2 tablespoons butter in heavy medium saucepan over medium heat until butter melts. Remove from heat. Add chocolate; let stand 1 minute. Whisk until chocolate melts and sauce is smooth. Mix in vanilla extract. Cool sauce to room temperature, stirring occasionally, about 30 minutes. Make ice cream cake: Line bottom of 9 x 5 x 2 1/2-inch metal loaf pan with parchment paper, leaving overhang on long sides. Using back of spoon, spread 1 pint ice cream over bottom of prepared pan. Sprinkle evenly with 1 cup cookie crumbs. Spread another 1 pint ice cream over cookie crumbs. Freeze until ice cream is firm, about 20 minutes. Spread with 3/4 cup sauce; freeze 20 minutes. Spread with remaining 1 pint ice cream; sprinkle with 1 cup cookie crumbs, pressing crumbs into ice cream to adhere. Cover pan and freeze ice cream cake until very firm, at least 4 hours. (Can be prepared 5 days ahead. Keep cake frozen. Cover and refrigerate remaining sauce. Store remaining 1 cup crumbs airtight at room temperature.) Stir remaining sauce in heavy medium saucepan over low heat until warmed through; pour into small pitcher or bowl. Cut around pan sides to loosen cake. Turn cake out onto platter. Peel off parchment. Sprinkle top of cake with remaining 1 cup crumbs. Cut cake crosswise into slices. Serve immediately with warm sauce.