1.Preheat oven to 180°C (160°C fan-forced). Line a 6-hole (Texas) or 12-hole standard muffin pan with paper cases.
2.In a small bowl, beat butter, extract, sugar, eggs, flour and milk with electric mixer on low speed until ingredients are just combined. Increase speed to medium, beat until mixture is changed to a paler colour.
3.Divide mixture among cases; smooth surface. Divide jam over top of cakes; using a skewer swirl jam into cakes.
4.Bake large cakes about 30 minutes, or small cakes about 20 minutes. Turn cakes on to a wire rack and cool.
5.To make fluffy frosting, combine sugar and water in a small saucepan; stir over heat, without boiling, until sugar is dissolved. Boil uncovered, without stirring, about 5 minutes or until syrup reaches 116°C on a sugar thermometer.
6.Syrup should be thick but not coloured. Remove from heat, allow bubbles to subside. Beat egg whites in small bowl with electric mixer until soft peaks form. While mixer is operating, add hot syrup in thin stream; beat on high speed about 10 minutes or until mixture is thick and cool.
7.Spread cakes with fluffy frosting and sprinkle with coloured sugar.