1.Preheat oven to 180°C. Line eight holes of 12-hole (80ml) muffin pan with paper cases.
2.Beat butter, extract, sugar, eggs, sifted flour and milk in small bowl with electric mixer on low speed until ingredients are combined. Increase speed to medium; beat until mixture has changed to a paler colour. Drop ¼ cups of mixture into paper cases.
3.Bake about 20 minutes. Stand cakes in pan 5 minutes before turning, top-side up, onto wire rack to cool.
4.Make glacé icing; sift icing sugar into small heatproof bowl; stir in butter and enough of the hot water to make a thick paste. Stir over small saucepan of simmering water until icing is spreadable. Tint icing pale blue with food colouring.
5.Make royal icing; sift icing sugar through a very fine sieve. Lightly beat egg white in small bowl with an electric mixer; beat in icing sugar, a tablespoon at a time. When icing reaches firm peaks, use a wooden spoon to beat in juice; cover tightly with plastic wrap to prevent drying out.
6.Working with one cold cake at a time, spread cake tops with glacé icing. Cut Mallow Bakes in half horizontally; pinch ends to make petals. Position five mallow halves for petals and a blue cachous in the centre of each cake before the icing has set.
7.Once the icing has set, half-fill a small piping bag (without a tube) with royal icing, pipe the flower stems on cakes.