Preheat oven to 180c.
Line 2 baking trays with parchment paper and set aside.
In a large bowl combine salted butter, Biscoff, granulated sugar and light brown sugar and beat together until fluffy and lighter in colour.
100 g salted butter, 150 g Biscoff cookie butter spread, 55 g granulated sugar, 100 g light brown sugar
Add in egg and vanilla and beat to combine.
1 egg, 2 teaspoon vanilla essence
Add plain flour to biscoff mixture, then sprinkle over bicarbonate of soda, cinnamon and salt.
190 g plain flour, ¾ teaspoon bicarbonate of soda, ½ teaspoon cinnamon, ¼ teaspoon fine salt
Beat again until just combined (don't overmix) then fold in chopped chocolate by hand.
70 g milk chocolate
Using a cookie scoop or by hand rolling, place balls of cookie dough (roughly 1½ tablespoon of mixture in each) onto lined baking sheets/trays, leaving room for cookies to spread.
Bake for 8 - 10 minutes.
Immediately when the cookies come out of the oven, give the baking tray a few raps on the counter.
Then take a drinking glass or mug a little larger than the cookies, place it upside down over a cookie and swirl it in a circle around the soft cookie.
Allow to cool on the tray for 10 minutes, then remove to a wire cooling rack to cool completely.