1.Preheat oven to 180°C/350°F. Grease 20cm x 30cm (8-inch x 12-inch) lamington pan; line with baking paper, extending paper 5cm (2-inches) over long sides.
2.Place butter and sugar in medium saucepan; stir over medium heat until butter is melted. Stir in sifted flour and egg yolk. Press mixture over base of pan.
3.Bake about 10 minutes or until browned lightly; cool.
4.Make fruit and nut topping. Beat eggs and sugar in small bowl with electric mixer until changed to a lighter colour and thickened slightly; fold in sifted flour. Transfer mixture to large bowl, stir in remaining ingredients.
5.Spread topping over cold base. Bake a further 30 minutes or until browned lightly. Cool in pan before cutting.
Store slice in an airtight container for up to one week.Note