Three Citrus Shortbread Bars

Preheat oven to 160°C (fan bake).

Crust: Combine all of the dry ingredients in a bowl then stir in the butter to make a soft dough. Tip into the tin and spread to a firm, even layer.

Bake for 18–20 minutes until a good golden colour. Reduce the oven temperature to 150°C.

Filling: Quarter the lemon and orange and remove any pips. Chop the fruit roughly and place in a food processor along with the sugar. Process until the fruit is well chopped but still has some texture.

Add all the remaining ingredients and process briefly to combine. Pour over the hot crust and bake for a further 45–55 minutes or until the mixture is fully set in the centre and the top is lightly golden. Leave to cool completely in the tin then chill if desired.

To serve: Holding the baking paper, carefully lift out of the tin. Dust with icing sugar and cut into squares or rectangles.  

Pantry note: If using a thick skinned lemon and orange, peel the fruit then using a sharp knife then carefully cut off the white pith, leaving only a thin layer on the skin. Too much white pith will make the slice taste bitter.

Cook's tip: I don’t know if it’s the acid content that varies in the fruit, but sometimes I have had to cook this slice for up to an hour before it’s fully set.