Preheat your oven to 180C and line a 9x9” square tin with baking paper with some overhang for easy removal.
Melt the butter in the microwave in 30 second bursts and let it cool for 10 minutes.
Beat the butter and sugar together. Then, whisk in the aquafaba until fully combined.
Stir in vanilla and biscoff spread (don’t over mix)
Stir in the flour (add it in slowly), salt, cinnamon and baking powder. The batter will be thick, more like a cookie dough.
Stir in most of the chocolate chips until evenly dispersed (leave a few for the top)
Add the batter to your lined tin and spread out evenly - I like doing this by putting a piece of baking paper on top and using this to flatten it out (prevents all the sticking). Add the rest of the chocolate chips to the top.
Bake for 25-28 minutes, or until skewer comes out clean and the top is set. Leave to cool fully before removing from the tin and slicing into squares. Store in an airtight container and enjoy!