Preheat the oven to 180C/350F (160C/320F fan-assisted).
In a large bowl, beat together the butter, Biscoff spread, golden syrup, vanilla and sugar until fluffy.
Add the flour, cocoa and baking powder and mix well – you should now have a sticky, light dough.
Add the chocolate chips and fold through.
Use a large ice cream scoop the dough, flattening off against the side of the bowl, then roll the dough into a ball with your hands. This is the best way to get 12 equally sized cookies.
Place the balls of dough on baking sheets lined with greaseproof paper, being sure to place each cookie at least an inch apart so that they don’t stick together when they spread.
Snap the Biscoff cookies in half and push one half on top of each ball of cookie dough, pressing down slightly.
Bake for 12-14 minutes until golden at the edges. Get them out of the oven while they're soft will ensure they stay crisp at the edges but soft and chewy in the middle when cool.
If the cookies lose their shape at all during cooking, you can reshape them while they're still hot. Place a tumbler over a cookie and gently move it in small circles to bring the cookie into a neat circle. Repeat with all of the cookies - this only works when they are fresh from the oven and soft.
Allow to cool on the tray until firm enough to transfer to a wire rack to cool completely.