1.Preheat oven to 180°C; grease and line deep 22cm-round cake pan. Make cake according to directions on packet, pour into pan; bake about 50 minutes. Stand cake in pan 5 minutes; turn onto wire rack to cool. Using serrated knife, level cake top.
2.Position cake on board, cut-side down. Using ruler and toothpicks, mark a 17cm circle in centre of cake. Using markings as a guide, cut shallow hollow into cake with small serrated knife.
3.To make butter cream, beat the butter (and any flavouring, if using) in a small narrow bowl with an electric mixer until the butter is as white as possible (this will result in a whiter butter cream which will give you better results if colouring it). Gradually beat in half the sifted icing sugar then the milk, then the remaining icing sugar. Beat until the butter cream is smooth and spreadable. Keep scraping down the side of the bowl during beating.
4.Tint butter cream with green colouring; spread all over cake.
5.Trim Fruit Sticks to the same height as cake; position around side of cake.
6.On surface dusted with icing sugar, knead icing until smooth. Knead yellow colouring into icing; roll until 5mm thick. Using the cardboard circle as a guide, cut circle from icing with sharp-pointed knife; position on centre of cake to cover hollow. Enclose remaining icing in plastic wrap.
7.Cut Raspberry Twisters in half lengthways; cut halves into 2.5cm pieces. Trim edges of pieces on an angle; position on cake for springs.
8.On surface dusted with icing sugar, roll reserved icing into 5mm cord; position around outside top edge of cake. Position dolls as desired.