Line 2 flat cookie sheets/trays with parchment/baking paper. Find a small pan or tray that fits in the freezer and line that with parchment paper as well.
Take heaping teaspoons of Biscoff spread and place apart on the small freezer friendly pan. Put in the freezer for 1 hour to harden.
Place butter, brown sugar and white sugar into the bowl of the mixer or bowl for the hand mixer and beat until light and creamy.
Add in egg and vanilla and beat till combined.
Add in flour, bicarb soda, salt and corn starch/flour and beat until mixed through.
Add in the white chocolate chips and fold through the cookie patter until they're evenly dispersed. (Optional: Reserve some of the chips for the tops of the cookies or use extra chips you may have on hand).
Take 2 tablespoons of mixture and roll into balls. Alternatively, use a 2 tablespoon cookie scoop.
Place onto prepared cookie sheets leaving about 3 inches between each cookie to allow for spreading. 6 should fit on each tray.
Remove the frozen Biscoff scoops from the freezer.
Working quickly take a ball of dough, make a whole in the centre and place a scoop of frozen Biscoff inside. Fold the rest of the dough over the Biscoff and roll to form a ball.
Place the trays in the fridge for at least 2 hours or overnight. If there is limited space in the fridge, place the balls close to each other on one tray. Seperate them onto 2 trays before baking.
Preheat oven to 180c/350F, 10-15 minutes before they're ready to bake.
Place in the oven for 10-12 minutes.
Cookies are ready when the edges are starting to turn golden in colour and the centres are still soft. The cookies will continue to cook and set on the tray after baking so it's best to take them out before they are baked through.
Serve slightly warm or cold.