Preheat the oven to 170°C (340°F). 

Melt the chocolate and the butter together au bain-marie.

In a large bowl add the eggs and mix until light and airy.

Add the sugar and mix to a pale and foamy mixture. When melted add the chocolate mixture to the eggs

In another bowl, sift the flour, cacao, baking powder and salt. Add this mixture to the eggs and fold in gently with a spatula. Don’t overmix.

Roughly break the Biscoff cookies in big pieces and carefully fold into the mixture.

Transfer the batter to the lined baking tin and smoothen it with a spatula.

Bake the brownies for 25-30 min in the oven. The middle should have a slight ‘wobble’.

Let it cool down in the tin, you can put the tin on a rack so that air can pass underneath.

Once it’s cooled, remove from the baking tin. Spread a thick layer of Biscoff spread over the brownie. Meanwhile, melt the dark chocolate (au bain marie).

Drizzle the melted dark chocolate in thin lines over the spread (you can use a spoon or a small piping bag).

Now use a skewer or toothpick to go back and forth over the Biscoff spread and chocolate (in the other direction) to create a feathered look.

Place the brownie in the fridge so it can cool off.