1.Preheat oven to 160°C (140°C fan-forced).
2.Grease a 20cm x 30cm rectangular pan; line base and long sides with baking paper, extending paper 5cm over sides.
3.Beat butter, caster sugar and egg in a small bowl with an electric mixer until light and fluffy. Stir in flours. Spread dough into pan. Combine marmalade and ginger in a small bowl; spread over dough.
4.Combine extra egg, 1 cup (80g) of the flaked almonds and ground almonds in a medium bowl. Spread almond mixture over marmalade; sprinkle with remaining nuts.
5.Bake for about 40 minutes. Cool in pan. Dust slice with icing sugar before cutting into squares and serving.
Store slice in an airtight container for up to a week.Note