1.Preheat oven to 170°C/340°F. Grease pan; line base and sides with baking paper, extending paper 5cm (2 inches) above sides.
2.Make cakes according to directions on packets. Spread mixture into pan; bake about 45 minutes. Stand cake in pan 10 minutes before turning, top-side up, onto wire rack to cool.
3.Meanwhile, make butter cream. Beat the butter in small narrow bowl with an electric mixer until the butter is as white as possible. 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.Level cake top; turn cake cut-side down. Using pattern from pattern sheet, cut out planter box; secure cake, cut-side down, to cake board with a little butter cream. Cut rim from cake; secure to top of planter box with a little butter cream.
5.Tint butter cream terracotta; spread all over cake.
6.Using picture as a guide, trim and position licorice strap to make the wrought iron pattern on planter box.
7.Slightly trim 3 apple licorice pieces to form 3 flower stems; secure to the cake board with a little butter cream. Secure 1 mint leaf at the side of each stem with a little butter cream.
8.Secure flying saucer lollies to cake board, above the stems, with a little butter cream, positioning them to make flower petals (use 5 flying saucers per flower). Secure a blackberry lolly to the centre of each flower with a little butter cream.
9.Cut remaining apple licorice into two 2cm/¾-inch pieces; carefully push the wooden skewer through the centre of each piece to make a hole. Push a lollipop stick through the hole in each piece of licorice; push the sticks into the top-edge of the planter box as far as they will go. Secure flying saucers to each lollipop with a little butter cream to make flowers. Secure a blackberry lolly to the centre of each flower with a little butter cream. Position remaining mint leaves in planter box to complete the flowers and leaves. (Insert toothpicks into the mint leaves to make it easier to position on cake, if necessary.)
Equipment: 20cm x 30cm (8-inch x 12-inch) rectangular cake pan, 35cm x 40cm (14-inch x 16-inch) rectangular cake board, wooden skewer and toothpicks.Note