1.Preheat oven to 180°C/160°C fan-forced. Grease deep 23cm-round cake pan; line base and side with baking paper.
2.In a medium bowl, beat butter, extract and sugar with electric mixer until light and fluffy. Beat in eggs, one at a time. Stir in sifted flour and milk, in two batches.
3.Divide mixture between two small bowls. Lightly crush raspberries in another small bowl with fork; gently stir crushed raspberries into one bowl of cake mixture. Drop alternate spoonfuls of mixtures into pan. Pull skewer back and forth through cake mixture for a marbled effect.
4.Bake cake about 1 hour. Stand cake in pan 5 minutes before turning, top-side up, onto wire rack to cool.
5.To make frosting, beat butter in small bowl with electric mixer until as white as possible; beat in sifted icing sugar and milk, in two batches.
6.Divide frosting between two small bowls; tint one bowl of frosting pink.
7.Spread plain frosting over cake; dollop cake with spoonfuls of pink frosting, swirl for a marbled effect.