First, preheat the oven to 170C fan.
1. Add the butter and brown sugar to the bowl of your stand mixer that is fitted with the K-beater attachment and mix on a medium speed for around three minutes.
2. Then, once the butter and sugar is fluffy and pale, add the vanilla and egg yolks and mix again on a medium speed.
3. Next, mix the bicarb into the flour using a spoon.
4. Add the flour into the stand mixer bowl and mix on a low speed until the flour is partly mixed in.
5. Then, add the chocolate chips and mix on a low speed.
6. Once the dough is ready, set to one side and line the tin with butter and two pieces of parchment so the cookie mixture won’t stick to the tin.
7. Divide the dough into three, it should weigh around 900g so each piece of the dough should be around 300g.
8. Add the first ball of dough into the tin and pat it down with the back of a spoon.
9. Then, on top of that add the Nutella and spread it out with a spoon, then repeat this process with the second layer of dough and Biscoff.
10. For the top layer pat the dough tin, before you add it to the top because it will start to be a bit unstable, then smooth the top layer with a spoon and it is ready to decorate with the m&m’s.
11. Bake the cookie for 35 minutes at 170c fan.
12. Let the cookie cool down and then place it in the fridge overnight and it will be ready to cut and enjoy the next day!