Preheat the oven to 350F
Add the flour and salt into a bowl, then rub in the butter using your fingertips.
Stir in the baking powder, baking soda, ginger and sugar.
Add the golden syrup and milk into the mix then stir everything together with a spatula until it forms a soft dough.
Break off and weigh out 7g pieces of dough, roll into a ball and place spaced apart on 3 baking sheets lined with baking parchment.
Bake for 8-10 minutes or until golden brown.
Remove the trays from the oven and leave the biscuits to cool for a few minutes before transferring to a wire rack to cool.
For the buttercream, add the ingredients to a bowl and beat until light, fluffy and smooth.
Turn half of the biscuits upside down and pipe a blob of buttercream onto each, then sandwich with the rest of the biscuits.
