Preheat oven to 180 C/ gas mk 4.
Turn an 8in square baking tin upside down and mould a piece of tin foil over it, turn the tin over and line with the moulded foil. Lightly grease the foil.
Melt the plain chocolate and butter in a medium pan over a low heat, stirring until smooth.
Stir in the sugars and stir for 2 minutes until the sugar has dissolved.
Beat in the eggs and vanilla essence
Stir in the flour. nuts and white chocolate.
Pour into the tin and bake for 20-25 minutes until a skewer(or a small sharp knife!)inserted 2 inches from the centre comes out clean.
Transfer the tin to a wire rack to cool down for 30 minutes. Using the foil lift from the tin and cool on the wire rack for 2 hours.
To make the topping
Melt the chocolate, butter, syrup, vanilla essence and coffee powder in a saucepan over a medium heat, stirring frequently, until smooth. Remove from the heat, chill for an hour until thickened and spreadable.
Invert the cake on to the rack, remove foil. Turn the right way up and spread a thick layer of the fudge glaze over the top. Chill for an hour until set.
Cut into squares or fingers
There is a lot of chocolate in this recipe so I tend to leave off the glaze and they still taste yummy