Grasshopper squares (mint chocolate brownies)

Method

• step 1

  To make the brownie layer, heat the oven to 180C/fan 160C/gas 4. Line a 22cm square tin with baking parchment, leaving some overhanging so you can lift the whole lot out easily. Melt the butter and chocolate together in a microwave or in a bowl set over a pan of simmering water. Cool to room temperature.

• step 2

  Whisk the eggs and sugar together until the mixture is pale and thickened. Fold the chocolate mixture into the egg mixture then sift over the flour, baking powder and cocoa. Fold this in to give a thick batter. Pour into the tin. Bake for 15-20 minutes, or until the top is cracked but the middle just set. Cool completely in the tin.

• step 3

  To make the mint layer, put the white chocolate in a bowl. Heat the cream until just simmering, then pour over the white chocolate. Leave for a minute then gently stir until the chocolate has melted. Stir in the peppermint and a tiny drop of food colouring so you have a pale mint colour. Leave to chill until thickened then spread on top of the cooled brownie and chill everything in the fridge for 45 minutes.

• step 4

  To make the chocolate icing, put the dark chocolate in a bowl with the syrup and butter. Gently melt in a microwave or in a bowl set over simmering water. Cool until it won’t melt the mint layers but is still spreadable, then spread on top of the mint layer. Chill for 1 hour until solid.

• step 5

  Lift the cake carefully onto a board. Peel away the baking paper, trim the edges, then cut into 9 squares with a sharp knife.