Preheat the oven to 170 °C (150 °C fan oven, 325 °F, gas 3). Grease and line an 18cm (7 inch) square cake tin. Break up the White Chocolate into pieces and place in a heatproof bowl with the butter. Put the bowl over a saucepan of gently simmering water. Leave to melt then remove from the water and cool for 10 minutes.

Beat the eggs and sugar into the melted chocolate. Sieve the flour and Baking Powder on top and add the Vanilla Extract and White Chocolate Chunks, and carefully fold into the mixture along until well combined.

Transfer to the prepared tin and smooth over the top. Bake in the oven for 25 minutes until risen, lightly golden and slightly crusty on top – the mixture should be slightly soft underneath. Leave to cool completely in the tin - the cake will sink slightly on cooling. Remove from the tin, and wrap and store for 24 hours to allow the texture to develop before serving.

For the dark brown sugar syrup, place 150g of the dark brown sugar in a small saucepan, and add 90ml (6 tbsp) of cold water. Heat gently, stirring, until the sugar dissolves, then stop stirring, raise the heat, bring to the boil and cook the sugar syrup for 2-3 minutes until syrupy. Then remove from the heat and leave to cool. 

To decorate, put the butter in a mixing bowl and beat until smooth and glossy. Gradually sift and beat in the icing sugar to make a stiff icing. Gradually mix in the 30ml (2 tbsp) dark sugar syrup and Caramel Flavour until smooth and fluffy.

Unwrap the blondie and place on a board. Spread over the caramel frosting. Cut into 16 equal portions. Your blondies are ready to serve and enjoy!