Beat together the butter, sifted icing sugar and extract until light and fluffy.

Sift the flours into the butter mixture and add 2 tablespoons of milk. Beat until well combined.

Place half the mixture onto a piece of plastic wrap and shape into a log. Roll up in the wrap until it is a smooth cylinder. Repeat with the other half of the mixture.

Refrigerate until firm (about 1 hour).

Preheat oven to about 160 degrees Celsius and line a baking tray with greaseproof paper.

Cut logs into 1 cm slices and place about 3cm apart on the trays. Bake for 20 minutes and then cool on wire rack.