Add the unsalted butter, light brown soft sugar and white granulated sugar to a bowl and beat together until creamy - I use my stand mixer with the beater attachment.
Add in the egg, egg yolk, and vanilla extract and beat again.
Add in the plain flour, cocoa powder, bicarbonate of soda, and salt and beat until a thick cookie dough is formed!
Add in the chopped chocolates and beat the cookie dough again until distributed well!
Split the cookie dough into three equal portions (about 475g each).
Line the bottom of a 8" springform cake tin (at least 2.75" in depth).
Press the first third of cookie dough onto the bottom of the cake tin.
Press the second third of cookie dough around the sides of the cake tin evenly.
Melt the biscoff spread for 20 seconds in the microave to loosen slightly or mix in a bowl briefly to loosen. Pour half into the cake tin inside the cookie dough case!
Add on the chopped biscuits
Pour on the rest of the Biscoff Spread.
Freeze the pie at this stage for an hour.
Once frozen, cover the top of the pie with the final third of cookie dough, making sure to seal it well!
Freeze the pie for another hour whilst you preheat the oven to 200°c for a regular oven, or 180°c for a fan oven like me.
Once chilled and the oven preheated, bake the pie for 30 minutes until the pie is lovely and golden on top. Leave to cool outside of the oven for an hour and do NOT remove from the tin.
Once cooled for an hour, put the pie in the fridge and chill for 5-6 hours (or preferably overnight!)
Once it has been chilled, carefully remove from the tin!
Using a large and sharp knife, portion the pie!
ENJOY!
Notes
If your oven runs hot you will want to reduce the temp slightly by 10°c so the pie doesn't burn.
If you want to reduce costs you can reduce the spread to 500g worth, but its will be shallower!
This cookie pie lasts 3-4+ days (best kept in the fridge!).