Beat together the butter and sugar using an electric whisk until light and creamy. Stir in the golden syrup.
Sift the flour, ginger and bicarb together, then combine with the butter mixture. Mix until a rough crumb begins to form, then work the mixture into a smooth dough using your hands. Refrigerate the dough for 15 minutes or until firm. (The longer the dough is chilled, the more it will keep its shape whilst baking.)
Preheat the oven to 180 C / Gas 4. Line a baking tray with baking parchment.
Roll out the dough until about 4mm thick, then cut out the gingerbread men shapes using a cutter. Place onto the prepared baking tray at least 1cm apart then add the Smarties® to make buttons.
Bake for 8 to 10 minutes, or until golden brown. Let cool on trays for a minute or two before removing to cool completely on wire racks.