Beat egg yolks, vanilla extract and sugar in medium mixing bowl until thick and pale; heat cream in pan until almost boiling; remove from heat; add cream gradually to egg mixture, beating constantly; stand bowl in hot water for 10 minutes, stirring occasionally, or until slightly thickened; set into the top of a double-boiler or a heatproof bowl set over a pan of simmering water; whisk for 5 minutes or until thickened; remove from heat; cover surface with plastic wrap.
For almond toffee: Line a tray with foil, grease lightly; combine sugar, water and almonds in a small pan; stir over medium heat for 3-4 minutes or until sugar dissolves; cook without stirring for 5-10 minutes or until deep amber in colour; do not allow to burn watch carefully pour onto tray; set aside until cold.
Finely crush the prepared almond toffee; fold 2/3s of it into warm custard; cool; when cold, fold through whipped cream.
Line a 21 X 14 X 7 cm loaf pan with a strip of foil; pour in custard mixture; freeze for 6 hours or overnight; invert ice cream onto serving platter.
For topping: Beat cream and sugar until soft peaks form, fold in liquor; spread over ice cream; sprinkle with reserved toffee; cut into slices to serve.