Step 1

Preheat oven to 180°C. Grease and line a 18 x 28cm base slab pan.

Step 2

Combine oats, flours, sugar, coconut, sultanas and cardamom in a large bowl.

Step 3

Place butter and golden syrup into a small saucepan. Stir over medium-low heat until melted. Stir butter mixture and egg into oat mixture and mix until well-combined. Spread into prepared pan and bake for 20 to 25 minutes. Allow to cool completely before icing.

Step 4

To make icing: Place icing mixture, cardamom and orange rind into a medium bowl. Gradually add orange juice until mixture is smooth and spreadable. Spread icing over slice. Put aside to set before cutting.