Preheat oven to 200°C (Gas mark 6/390°F). Line 2 large baking trays with baking paper.
Place the butter, sugars and golden syrup in a saucepan. Stir over a low heat until completely melted.
Sieve the flour, bicarbonate of soda and spices into a large bowl. Pour in the melted butter and sugar mixture and mix until completely combined.
Once cool enough to handle, pull the mixture together with your hands and knead to a stiff dough.
Roll out the dough between sheets of greaseproof paper to around 0.75cm thick.
Use a small star shaped cookie cutter to cut stars from the gingerbread, then carefully transfer to the lined trays.
Bake the stars for 8-10 minutes
Once cooked, leave the gingerbread stars to cool on the baking trays for a few minutes then transfer to a cooling rack to finish cooling.
Once the gingerbread stars are completely cool, make up the royal icing according to pack instructions. Your icing should be fairly stiff and suitable for piping. Add the gel colouring and whisk in until evenly coloured.
Spoon the icing into a piping bag with a small round piping tip.
Pipe decorative patterns onto the stars, then leave the icing to dry and set – this may take a couple of hours.
Once the icing has completely dried, store the gingerbread stars in an airtight container, layered with baking paper to separate them, until ready to serve.