Make the crepe batter

• Combine the cornstarch, sugar, flour and cocoa powder in a bowl.
• Slowly whisk in the milk, then crack in the eggs.
• Add the melted butter and whisk until smooth, like a jug of chocolate milk.

Strain the batter

• Pour the batter through a sieve into a jug to remove any lumps.

Cook the crepes

• Heat a lightly buttered frying pan over medium heat.
• Pour in a thin layer of batter, swirl to coat and cook until set.
• Flip and cook the other side briefly, then transfer to a plate. Repeat with the remaining batter.

Make the chocolate filling

• Combine the cold cream, sugar and cocoa powder in a bowl.
• Whisk until thick and fluffy.

Assemble the cake

• Place a crepe on a plate and spread with chocolate cream.
• Top with another crepe and repeat, alternating crepes and cream, until all are used.
• Finish with a layer of cream on top.

Chill and serve

• Refrigerate the cake so the layers set before slicing.