Step 1

Place the washed unpeeled mandarins in an 18-cup (4.5L) slow cooker. Cover with hot water. Cook, covered, on high for 2 hours. Trim the ends from mandarins and discard. Halve the mandarins and discard the seeds. Place in a food processor and process until the mixture is pulpy.

Step 2

Grease and line a 20cm round (base measurement) cake pan with baking paper. Use an electric mixer to beat the eggs and sugar in a bowl until thick and creamy. Add the almond meal, flour and mandarin pulp and use a large metal spoon to gently fold until just combined. Spoon into the prepared pan. Top the pan with a sheet of baking paper and foil, pleated in the centre. Secure with kitchen string. Place the pan in the slow cooker. Add enough boiling water to come halfway up the side of the pan. Cook, covered, on high, adding more boiling water to the slow cooker as necessary, for 3 hours. Stand cake in the pan for 5 mins to cool before turning onto a wire rack to cool completely.

Step 3

Meanwhile, use a small serrated knife to cut the extra unpeeled mandarins into thin slices. Combine the extra sugar and 1/4 cup (60ml) water in a small frying pan over medium-low heat. Cook, stirring, for 2-3 mins or until sugar dissolves. Add the sliced mandarin and reduce heat to very low. Cook for 6-8 mins or until mandarin is tender and the syrup thickens. Set aside to cool.

Step 4

Place the cake on a serving platter. Use a clean electric mixer to whisk the cream in a bowl until soft peaks form. Spoon whipped cream over the top of the cake. Top with the mandarin slices and syrup to serve.