Line 2 (9- x 5-inch) loafpans with plastic wrap, allowing excess to hang over sides.
Stir together 1 tablespoon coffee liqueur and instant coffee granules until dissolved. Combine coffee mixture, chocolate ice cream, and half of the chopped toffee in a large bowl. In a separate bowl, combine 1/2 gallon coffee ice cream and remaining chopped toffee. Spread half of chocolate ice-cream mixture evenly into 1 prepared loafpan; top with half of coffee ice-cream mixture. Repeat layers in remaining loafpan.
Brush ladyfingers with 3 tablespoons coffee liqueur; place ladyfingers, brushed sides down, evenly over ice cream in loafpans. Fold plastic wrap over to seal; freeze at least 8 hours.
Stir together brewed coffee, sugar, and cornstarch in a heavy saucepan over medium-high heat; cook, stirring constantly, until mixture starts to boil. Reduce heat to low, and cook 2 to 3 minutes or until thickened and clear. Remove from heat; cool. Stir in remaining 2 tablespoons liqueur; cover and chill coffee sauce until ready to serve.
Invert tortes onto serving plates; remove and discard plastic wrap. Garnish, if desired. Serve with chilled coffee sauce.
Note: For testing purposes only, we used Hershey's Heath Snack Bars.
In place of coffee liqueur, feel free to use the same amount of sweetened, brewed coffee.