Macaroons:
4 eggs - separated
1 cup of Chelsea Caster Sugar
75g dark chocolate
200g ground almonds
¼ cup dark cocoa powder

Filling:
100g Oreo biscuits
125g dark chocolate

Preheat oven to 120°C and line 3 oven trays with baking paper.

For the Macarons:
Beat egg whites and Chelsea Caster Sugar with an electric mixer for 12-15 minutes until stiff white peaks form.
Break 75g of dark chocolate into a heatproof bowl and melt in the microwave on medium for 1-2 minutes.
Fold in ground almonds, sifted dark cocoa powder and the melted chocolate into egg mixture until combined.
Fit a large piping bag with a 1cm plain tube and fill with mixture.
Pipe mixture onto trays in 5cm circles.
Bake for 45 minutes until crisp to touch, then cool on a wire rack.

Filling:
Process Oreo biscuits in a food processor until finely crushed.
Melt 125g of dark chocolate as above and add to processor with biscuit crumbs.
Process until combined.
Sandwich macarons together with chocolate Oreo filling and allow to set.