1.Preheat oven to 180°C/350°F. Line eight holes of 12-hole (¹/³-cup/80ml) muffin pan with paper cases.
2.Beat butter, rosewater, sugar, eggs, sifted flour and milk in small bowl with electric mixer on low speed until 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 fluffy mock cream: combine milk, the water and sugar in small saucepan; stir over low heat, without boiling, until sugar is dissolved. Sprinkle gelatine over extra water in cup, add to pan; stir syrup until gelatine is dissolved. Cool mixture to room temperature. Beat butter and extract in small bowl with electric mixer until as white as possible. While motor is operating, gradually pour in cold syrup; beat until light and fluffy. The mixture will thicken on standing.
5.Spoon into a large piping bag fitted with a large fluted tube. Pipe stars on top of each cake. Cut marshmallows in half horizontally; dip sticky sides into pink sugar sprinkles. Pinch one end of each marshmallow half to make a petal shape. Use five halves to make each frangipani, using more pink sprinkles to fill in any white gaps on the marshmallows.