To melt the chocolate
Place the chocolate and butter in a thin-sided bowl and suspend over a gently simmering bain-marie, ensuring that the bowl does not touch the water. Remove the pan from the heat, allow the chocolate and butter to melt, stir until smooth, allow to cool slightly.
Beat the eggs, sugar, vanilla sugar and salt using the whisk on a hand mixer until the mixture becomes lighter in colour. Stir in the chocolate and butter mixture. Mix the nuts, chocolate, flour and baking powder and stir in. Transfer the blondie mixture to the prepared tin.
Approx. 30 mins. in the lower half of an oven preheated to 180°C. The blondies should still be a little gooey inside. Remove from the oven, allow to cool slightly, remove from the tin, cut into pieces, leave the blondies to cool on a rack.