Preheat the oven to 180 degrees Celsius (fan) and line an 8 x 8 inch tin with greaseproof paper.

In a medium bowl, sift together the cocoa powder and all-purpose flour.

Melt the dairy-free chocolate and butter in a heatproof bowl over simmering water, stirring until smooth, then remove from heat.

Whip the aquafaba and half of the caster sugar until thick and glossy.

Fold the melted chocolate mixture into the whipped aquafaba, then sift in the flour and cocoa, folding until combined.

Add the chopped Biscoff biscuits and gently mix to combine.

Pour the brownie batter into the prepared tin and smooth the top.

Bake for 30-35 minutes, then allow to cool.

For the Biscoff spread layer, heat the Biscoff spread until melted and pour it over the cooled brownies, refrigerate to set.

Blend the dairy-free yogurt, remaining sugar, melted butter, silken tofu, and Biscoff spread until smooth.

Pour the creamy mixture over the set Biscoff layer and smooth the top.

Sprinkle with crushed Biscoff biscuits and refrigerate overnight.

Once set, remove from the tin, cut into squares, and serve at room temperature.