Instructions

Step 1
Preheat the oven to 160C/140C fan forced. Grease a round 20cm cake pan and line the base with baking paper.
Combine the sugar, 125g butter and 250ml (1 cup) water in a saucepan. Place over medium-low heat and cook, stirring occasionally, for 3-5 minutes until the butter has melted and the sugar has dissolved. Set aside to cool to room temperature.
Step 3
Sift the flours and cocoa powder into a large bowl and make a well in the centre. Add the cooled butter mixture and the eggs and use a metal spoon to gently fold until just combined. Pour into the prepared pan. Bake for 50 minutes or until a skewer inserted into the centre comes out clean. Set aside for 10 minutes to cool slightly before turning out onto a wire rack to cool completely.
Step 4
Combine the chocolate and the remaining 125g butter in a heatproof bowl over a saucepan of simmering water (make sure the bowl doesn’t touch the water). Cook, stirring occasionally, for 5 minutes or until melted and smooth. Set aside to cool for about 20 minutes or until a spreadable consistency.
Step 5
Divide the Smarties into separate colours. Reserve about 1/4 cup chocolate mixture and set aside. Spread the remaining chocolate mixture over the top and side of the cake. Working quickly, arrange the Smarties in colour-coded rows, over the cake, pressing gently into the icing. If the chocolate mixture starts to set before you’ve finished decorating, warm the reserved chocolate mixture and use it to attach the remaining Smarties.