Line 2 x 12-section bun trays with paper cake cases. Put all the cake ingredients in a bowl and beat with a hand-held electric whisk for about a minute until light and creamy. Divide the cake mixture between the paper cases.
Bake in a preheated oven, 180°C (350°F), Gas Mark 4, for 20 minutes or until just firm to the touch – the cakes on the lower oven shelf may need a little longer, but don't swap the trays halfway through cooking or the cakes could sink. Transfer to a wire rack to cool.
Roll out the pale pink icing thinly on a work surface lightly dusted with icing sugar. Stamp out 12 flower shapes using a cutter about 4 cm (1¾ inches) in diameter. Cup each flower slightly in the palm of your hand and transfer to a sheet of crumpled foil to harden. Roll out the deep pink icing and make 12 more flowers. Take a tiny piece of pale pink icing from the trimmings and press against a piece of tuille until the netting leaves an impression in the icing. Peel away the tuille. Press the icing gently into the centre of a deep pink flower. Repeat for the remaining flowers, alternating the pinks.
Put 200 ml (7 fl oz) of the cream in a small saucepan and bring almost to the boil. Pour over the chocolate in a bowl and leave until it has melted, stirring occasionally until smooth. Leave to cool.
Stir the remaining cream into the chocolate mixture and whip until just holding its shape – don't overwhip or the mixture will start to separate. Pipe or spoon over the cakes. Decorate with the prepared flowers.