Nanaimo Bars

Instructions

1. 1 Line a twenty-centimetre square baking pan with parchment paper, leaving an overhang on two sides for easy lifting later. This makes removal and clean cutting much easier once the bars have set.
2. 2 Melt the base butter in a saucepan over low heat. Whisk in the sugar and cocoa powder until smooth, then add the beaten egg and cook, stirring constantly, for two to three minutes until the mixture thickens slightly. Remove from heat.
3. 3 Stir the graham cracker crumbs, desiccated coconut, and chopped walnuts into the chocolate mixture until everything is evenly combined. Press this mixture firmly and evenly into the prepared pan using the back of a spoon or measuring cup.
4. 4 For the middle layer, beat the softened butter with the icing sugar, custard powder, and cream until light and fluffy, about three minutes with an electric mixer. Spread this custard layer evenly over the compressed base using an offset spatula.
5. 5 Refrigerate the pan for at least thirty minutes until the custard layer is firm to the touch. This step prevents the warm chocolate topping from melting into the custard and muddying the clean layer separation.
6. 6 Melt the dark chocolate and butter together in a heatproof bowl set over simmering water, stirring until smooth and glossy. Let it cool for two minutes, then pour over the chilled custard layer, tilting the pan to spread it evenly.
7. 7 Refrigerate for at least two hours until the chocolate is completely set and firm. Use the parchment overhang to lift the slab from the pan, then cut into bars using a sharp knife dipped in hot water for clean edges.