Nanaimo Bars

Method

1. Line a 20×10 cm square tin with baking paper, leaving some hanging over the sides so you can lift the slice out later. Pour about 3 cm of water into a small pot and heat it over low heat until barely simmering, then set a heatproof bowl on top (the bottom must not touch the water). Put the butter, sugar and cocoa in the bowl and stir for 3 min, until melted and smooth.

   Add in this stepUnsalted butter (base) 58 gGranulated sugar 25 gUnsweetened cocoa powder 15 g

   low heat

2. Stir in the beaten egg a little at a time and keep stirring over low heat for 2 min, until the mixture thickens like custard and looks glossy (71 °C if you have a thermometer). Stir constantly so the egg doesn't scramble. Lift the bowl off the heat.

   Add in this stepBeaten egg 25 g

   low heat

3. Mix in the crumbs, coconut and chopped nuts. Tip into the tin and press down firmly with the bottom of a glass to make a solid, even layer. Chill in the fridge for 15 min.

   Add in this stepGraham cracker crumbs (or digestive biscuit crumbs) 75 gDesiccated coconut 40 gWalnuts or almonds, finely chopped 30 g

4. Put the softened filling butter, cream and custard powder in a bowl and beat with an electric mixer, then add the icing sugar a little at a time and beat for 2 min, until pale yellow, smooth and spreadable. If it is too stiff, add a few drops more cream.

   Add in this stepUnsalted butter (filling, softened) 58 gDouble cream or milk 20 mlCustard powder 1 tbspIcing sugar 125 g

5. Spread the filling over the chilled base, right to the edges, and smooth the top with a spatula. Chill for 30 min, until firm enough that it doesn't stick to your finger.

6. Set the bowl over barely simmering water again (low heat) and stir the chocolate and topping butter for 2 min, until melted. Take it off the heat and let it cool for 5 min, until just lukewarm; hot chocolate melts the filling. Pour it thinly over the cold filling and spread it evenly.

   Add in this stepSemi-sweet chocolate, chopped 58 gUnsalted butter (topping) 14 g

   low heat

7. Chill for 20 min, just until the chocolate has set (left too long, it cracks when cut). Lift out by the paper and cut into 2×4 pieces (rows × columns), dipping the knife in hot water and wiping it between cuts.