Preheat oven to 170C bake or 150C fan bake
Line 3 large baking trays with baking paper
Sift flours, ginger and baking soda together
Using an electric mixer, beat butter, raw caster sugar and golden syrup until light and fluffy
Add eggs, one at a time, beating until combined after each addition
Beat on medium speed for 2 minutes or until creamy (mixture may appear curdled at this stage)
Add half the flour mixture. Beat on low speed until combined. Repeat with the remaining flour mixture. Stand for 5 minutes.
Spoon two level teaspoons of mixture, on top of each other, onto prepared trays. Repeat with the remaining mixture, leaving 5cm between each for spreading.
Bake, one tray at a time, for 13 to 15 minutes or until golden and just firm to touch. Cool on trays.
Using an electric mixer, beat butter until light and fluffy. Gradually beat in the icing sugar until well combined 11. Beat in golden syrup
Spread two to three teaspoons of filling onto the flat side of half of the biscuits
Sandwich with remaining biscuits
