Step 1

Preheat oven to 180C/160C fan-forced. Grease a 6cm-deep, 19cm square cake pan. Line base and sides with baking paper.

Step 2

Using an electric mixer, beat butter, sugar and vanilla until light and fl uffy. Add eggs, 1 at a time, beating well after each addition. Stir in flour and milk, in 2 batches, until combined. Divide mixture evenly among 3 bowls.

Step 3

Tint 1 portion of mixture pink. Add cocoa to 1 remaining portion, stirring to combine. Keep remaining mixture plain. Spoon mixtures, 1 tablespoon at a time, alternately into prepared pan. Run a butter knife back and forth through mixture to create a marbled effect. Level top with a spatula.

Step 4

Bake for 50 minutes to 1 hour or until a skewer inserted into centre of cake comes out clean. Stand in pan for 5 minutes. Turn, top-side up, onto a baking paper-lined wire rack to cool completely.

Step 5

Make icing Using electric mixer, beat butter and vanilla for 5 minutes or until light and fluffy. Gradually beat in sugar until well combined. Tint pink with food colouring. Spread icing over top of cake. Serve.