Pre-heat the oven to 175°C (350ºF) and line a baking tray with grease-proof paper.
Beat the butter and sugar together until nice and fluffy and then beat in the syrup.
Sift the flour, cinnamon and baking powder together and then stir into the butter/sugar mixture. You should be left with a dough that comes together easily and can be rolled out, although it will be a little on the sticky side.
Roll the dough out into a fairly long rectangular shape, around 25cm long and 14cm across. It will probably find it easier to roll the dough out on the grease-proof paper and then transfer to the baking tray (the thinner the dough, the crunchier the cookie).
Bake for around 10 minutes until the cookies are a golden brown colour (slightly darker at the edges). Do not overbake!
Remove from the oven and immediately cut them diagonally into strips. The cookies will be soft but slightly crumbly, so cut gently (do not leave them to cool before cutting).
Allow the cookies to cool completely and then put three aside to use as decoration. For the remaining cookies, blitz them in a food processor until they are fairly fine crumbs. Put to one side.