This radiant dessert will delight all of your friends this St Patrick's Day. The perfect thing to soak up all that Irish stout...
- Heat oven to 170C/350F.
- Pour your stout into a small pan and bring to boil. Reduce by half, then leave to cool.
- In a heatproof bowl set over a pan of simmering water, place your dark chocolate and butter and melt over a low heat until totally smooth. Leave to cool slightly for 2 mins.
- Add the sugar to the chocolate mixture and whisk with a hand whisk until incorporated. Add the flour and whisk again until incorporated, then add your beaten eggs and cooled stout and whisk for 1 min until the mixture is totally smooth and airy.
- Spoon the mixture into 23cm square tin lined with baking parchment and bake for 20 mins until the mixture is firm. Leave in the tin for 10 mins, then place on a wire rack to cool.
- Put your custard and green food colouring in a saucepan and warm over a medium heat, stirring to combine until the custard is totally green. Put in a bowl, close cover with clingfilm and leave to cool.
- Place your cream, icing sugar and peppermint essence in a large bowl. Whisk on a medium speed until your cream is thick and whipped.
- Place your dark chocolate, milk chocolate and double cream in a heatproof bowl over a simmering pan. Leave until the chocolate is melted, then stir to combine to a smooth sauce.
- Cut your brownies into cubes and lay half on the base of the dish. Drizzle with chocolate sauce, then pour some of the custard over the top, then the cream. Repeat with another layer of brownies, chocolate sauce, custard and cream, then top with some halved mint sandwich cookies and drizzle with chocolate sauce. Serve!