Method

• 1.
  Preheat the oven to 180°C. Grease and line the base and sides of a 20cm square cake pan with baking paper.
• 2.
  Place the butter and 200g white chocolate in a heatproof bowl set over a saucepan of gently simmering water (don’t let the bowl touch water) and stir until melted. Remove from heat.

• 3.
  Transfer chocolate mixture to a large bowl and stir in sugar, egg, banana and vanilla. Sift over the flour and baking powder, stir to combine, then fold in the nuts and dark chocolate chips.
• 4.
  Pour the batter into the pan and bake for 35 minutes or until golden. Cool the blondies completely in the pan.
• 5.
  Melt remaining 50g white chocolate. Cut the blondies into squares, dust with icing sugar and drizzle with melted chocolate to serve.